Data yang akan Diolah

BAB 4 PENGOLAHAN DATA

4.1 Data yang akan Diolah

Pengambilan data dilakukan di Kantor Badan Pusat Statistik Sumatera Utara, data yang diambil adalah data perolehan nilai air minum yang disalurkan PDAM Tirtanadi Medan pada tahun 2009 sampai dengan 2011. Tabel 4.1 Data Nilai Air Minum yang Disalurkan PDAM Medan Tahun 2009 - 2011 Bulan Tahun Nilai Air Minum yang Disalurkan Januari 09 21.473.831.050 Februari 09 21.548.149.420 Maret 09 21.789.329.725 April 09 22.005.291.800 Mei 09 22.264.141.990 Juni 09 22.481.546.105 Juli 09 22.851.209.020 Agustu 09 22.845.663.820 Septembe 09 22.927.399.070 Oktober 09 22.854.910.720 November 09 22.764.705.655 Desember 09 22.819.191.990 Januari 010 22.977.014.134 Februari 010 22.942.268.240 Maret 010 23.444.261.325 April 010 23.821.534.330 Mei 010 24.200.283.345 Juni 010 24.451.483.354 Juli 010 24.403.585.445 Agustus 010 24.272.090.440 September 010 24.082.631.404 Oktober 010 24.551.663.651 November 010 24.612.143.420 Desember 010 20.195.839.321 Universitas Sumatera Utara Universitas Sumatera Utara Lanjutan Tabel 4.1 Januari 011 18.547.485.425 Februari 011 22.317.670.660 Maret 011 23.490.850.795 April 011 23.401.919.900 Mei 011 24.440.969.550 Juni 011 25.113.931.440 Juli 011 25.401.258.645 Agustus 011 25.321.323.110 September 011 25.080.556.135 Oktober 011 25.109.569.925 November 011 25.282.275.715 Desember 011 25.569.779.015 Sumber : BPS Sumatera Utara Dari data pada Tabel 4.1 di atas, untuk perolehan nilai air minum yang disalurkan maka penulis akan menganalisis data tersebut dan meramalkan perolehan nilai air minum yang disalurkan untuk tahun 2009 – 2011 dengan menggunakan metode pemulusan Smoothing Eksponensial Ganda. Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,1 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,1 21.548.149.420,00+1-0,1 21.473.831.050,00 = 21.481.262.887,00 Maret 2009 = 0,1 21.789.329.725,00+1-0,1 21.481.262.887,00 = 21.512.069.570,80 Universitas Sumatera Utara Universitas Sumatera Utara Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,1 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,121.481.262.887,00+1-0,121.473.831.050,00 = 21.474.574.233,70 Maret 2009 = 0,121.512.069.570,80+1-0,121.474.574.233,70 = 21.478.323.767,41 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.481.262.887,00 – 21.474.574.233,70 = 21.487.951.540,30 Maret 2009 = 221.512.069.570,80 - 21.478.323.767,41 = 21.545.815.374,19 Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,1 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.481.262.887,00 – 21.474.574.233,70 = 743.183,70 Maret 2009 = , , 21.512.069.570,80 - 21.478.323.767,41 = 3.749.533,71 Universitas Sumatera Utara Universitas Sumatera Utara Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.487.951.540,30 + 743.183,70 1 = 21.488.694.724,00 F April 2009 untuk m = 1 = 21.545.815.374,19 + 3.749.533,71 1 = 21.549.564.907,90 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,481,262,887.00 21,474,574,233.70 21,487,951,540.30 743,183.70 Maret 3 21,789,329,725.00 21,512,069,570.80 21,478,323,767.41 21,545,815,374.19 3,749,533.71 21,488,694,724.00 300,635,001.00 90,381,403,826,270,000.00 April 4 22,005,291,800.00 21,561,391,793.72 21,486,630,570.04 21,636,153,017.40 8,306,802.63 21,549,564,907.90 455,726,892.10 207,687,000,183,131,000.00 Mei 5 22,264,141,990.00 21,631,666,813.35 21,501,134,194.37 21,762,199,432.32 14,503,624.33 21,644,459,820.03 619,682,169.97 384,005,991,778,729,000.00 Juni 6 22,481,546,105.00 21,716,654,742.51 21,522,686,249.19 21,910,623,235.84 21,552,054.81 21,776,703,056.66 704,843,048.34 496,803,722,800,268,000.00 Juli 7 22,851,209,020.00 21,830,110,170.26 21,553,428,641.29 22,106,791,699.23 30,742,392.11 21,932,175,290.65 919,033,729.35 844,622,995,674,335,000.00 Agustus 8 22,845,663,820.00 21,931,665,535.24 21,591,252,330.69 22,272,078,739.78 37,823,689.39 22,137,534,091.34 708,129,728.66 501,447,712,615,046,000.00 September 9 22,927,399,070.00 22,031,238,888.71 21,635,250,986.49 22,427,226,790.93 43,998,655.80 22,309,902,429.18 617,496,640.82 381,302,101,426,542,000.00 Oktober 10 22,854,910,720.00 22,113,606,071.84 21,683,086,495.03 22,544,125,648.66 47,835,508.54 22,471,225,446.74 383,685,273.26 147,214,388,919,231,000.00 Oktober 11 22,764,705,655.00 22,178,716,030.16 21,732,649,448.54 22,624,782,611.78 49,562,953.51 22,591,961,157.19 172,744,497.81 29,840,661,523,040,500.00 Desember 12 22,819,191,990.00 22,242,763,626.14 21,783,660,866.30 22,701,866,385.98 51,011,417.76 22,674,345,565.29 144,846,424.71 20,980,486,751,720,300.00 2010 Januari 13 22,977,014,134.00 22,316,188,676.93 21,836,913,647.36 22,795,463,706.49 53,252,781.06 22,752,877,803.74 224,136,330.26 50,237,094,540,662,800.00 Februari 14 22,942,268,240.00 22,378,796,633.23 21,891,101,945.95 22,866,491,320.52 54,188,298.59 22,848,716,487.56 93,551,752.44 8,751,930,385,451,990.00 Maret 15 23,444,261,325.00 22,485,343,102.41 21,950,526,061.60 23,020,160,143.23 59,424,115.65 22,920,679,619.11 523,581,705.89 274,137,802,745,642,000.00 April 16 23,821,534,330.00 22,618,962,225.17 22,017,369,677.95 23,220,554,772.39 66,843,616.36 23,079,584,258.87 741,950,071.13 550,489,908,045,325,000.00 Mei 17 24,200,283,345.00 22,777,094,337.15 22,093,342,143.87 23,460,846,530.43 75,972,465.92 23,287,398,388.74 912,884,956.26 833,358,943,357,364,000.00 Juni 18 24,451,483,354.00 22,944,533,238.84 22,178,461,253.37 23,710,605,224.31 85,119,109.50 23,536,818,996.35 914,664,357.65 836,610,887,149,449,000.00 Juli 19 24,403,585,445.00 23,090,438,459.45 22,269,658,973.98 23,911,217,944.93 91,197,720.61 23,795,724,333.80 607,861,111.20 369,495,130,506,146,000.00 Agustus 20 24,272,090,440.00 23,208,603,657.51 22,363,553,442.33 24,053,653,872.69 93,894,468.35 24,002,415,665.54 269,674,774.46 72,724,483,980,818,800.00 September 21 24,082,631,404.00 23,296,006,432.16 22,456,798,741.31 24,135,214,123.00 93,245,298.98 24,147,548,341.04 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 23,421,572,154.04 22,553,276,082.59 24,289,868,225.50 96,477,341.27 24,228,459,421.98 323,204,229.02 104,460,973,653,456,000.00 Oktober 23 24,612,143,420.00 23,540,629,280.64 22,652,011,402.39 24,429,247,158.88 98,735,319.81 24,386,345,566.77 225,797,853.23 50,984,670,523,114,500.00 Desember 24 20,195,839,321.00 23,206,150,284.67 22,707,425,290.62 23,704,875,278.73 55,413,888.23 24,527,982,478.69 -4,332,143,157.69 18,767,464,338,712,800,000.00 2011 Januari 25 18,547,485,425.00 22,740,283,798.71 22,710,711,141.43 22,769,856,455.98 3,285,850.81 23,760,289,166.96 -5,212,803,741.96 27,173,322,852,155,300,000.00 Februari 26 22,317,670,660.00 22,698,022,484.84 22,709,442,275.77 22,686,602,693.90 -1,268,865.66 22,773,142,306.79 -455,471,646.79 207,454,421,032,716,000.00 Maret 27 23,490,850,795.00 22,777,305,315.85 22,716,228,579.78 22,838,382,051.93 6,786,304.01 22,685,333,828.24 805,516,966.76 648,857,583,732,697,000.00 April 28 23,401,919,900.00 22,839,766,774.27 22,728,582,399.23 22,950,951,149.31 12,353,819.45 22,845,168,355.94 556,751,544.06 309,972,281,818,187,000.00 Mei 29 24,440,969,550.00 22,999,887,051.84 22,755,712,864.49 23,244,061,239.19 27,130,465.26 22,963,304,968.76 1,477,664,581.24 2,183,492,614,660,820,000.00 Juni 30 25,113,931,440.00 23,211,291,490.66 22,801,270,727.10 23,621,312,254.21 45,557,862.62 23,271,191,704.45 1,842,739,735.55 3,395,689,732,958,810,000.00 Juli 31 25,401,258,645.00 23,430,288,206.09 22,864,172,475.00 23,996,403,937.18 62,901,747.90 23,666,870,116.82 1,734,388,528.18 3,008,103,566,665,410,000.00 Agustus 32 25,321,323,110.00 23,619,391,696.48 22,939,694,397.15 24,299,088,995.81 75,521,922.15 24,059,305,685.08 1,262,017,424.92 1,592,687,980,809,830,000.00 September 33 25,080,556,135.00 23,765,508,140.33 23,022,275,771.47 24,508,740,509.20 82,581,374.32 24,374,610,917.96 705,945,217.04 498,358,649,461,600,000.00 Oktober 34 25,109,569,925.00 23,899,914,318.80 23,110,039,626.20 24,689,789,011.40 87,763,854.73 24,591,321,883.52 518,248,041.48 268,581,032,502,130,000.00 Oktober 35 25,282,275,715.00 24,038,150,458.42 23,202,850,709.42 24,873,450,207.42 92,811,083.22 24,777,552,866.13 504,722,848.87 254,745,154,170,497,000.00 Desember 36 25,569,779,015.00 24,191,313,314.08 23,301,696,969.89 25,080,929,658.27 98,846,260.47 24,966,261,290.64 603,517,724.36 364,233,643,619,284,000.00 SE 9,810,307,676.54 SSE 64,932,716,351,400,500,000.00 M SE 1,909,785,775,041,190,000.00 Tabel 4.2 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,1 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,2 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,2 21.548.149.420,00+1-0,2 21.473.831.050,00 = 21.488.694.724,00 Maret 2009 = 0,2 21.789.329.725,00+1-0,2 21.488.694.724,00 = 21.548.821.724,20 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,2 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,2 21.488.694.724,00+1-0,2 21.473.831.050,00 = 21.476.803.784,80 Maret 2009 = 0,2 21.548.821.724,20+1-0,2 21.476.803.784,80 = 21.491.207.372,68 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.488.694.724,00 – 21.476.803.784,80 = 21.500.585.663,20 Maret 2009 = 221.548.821.724,20 - 21.491.207.372,68 = 21.606.436.075,72 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,2 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.488.694.724,00 – 21.476.803.784,80 = 2.972.734,80 Maret 2009 = , , 21.548.821.724,20 - 21.491.207.372,68 = 14.403.587,88 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.500.585.663,20 + 2.972.734,80 1 = 21.503.558.398,00 F April 2009 untuk m = 1 = 21.606.436.075,72 + 14.403.587,88 1 = 21.620.839.663,60 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,488,694,724.00 21,476,803,784.80 21,500,585,663.20 2,972,734.80 Maret 3 21,789,329,725.00 21,548,821,724.20 21,491,207,372.68 21,606,436,075.72 14,403,587.88 21,503,558,398.00 285,771,327.00 81,665,251,335,340,900.00 April 4 22,005,291,800.00 21,640,115,739.36 21,520,989,046.02 21,759,242,432.70 29,781,673.34 21,620,839,663.60 384,452,136.40 147,803,445,182,522,000.00 Mei 5 22,264,141,990.00 21,764,920,989.49 21,569,775,434.71 21,960,066,544.27 48,786,388.69 21,789,024,106.04 475,117,883.96 225,737,003,658,631,000.00 Juni 6 22,481,546,105.00 21,908,246,012.59 21,637,469,550.29 22,179,022,474.89 67,694,115.58 22,008,852,932.96 472,693,172.04 223,438,834,893,234,000.00 Juli 7 22,851,209,020.00 22,096,838,614.07 21,729,343,363.04 22,464,333,865.10 91,873,812.76 22,246,716,590.47 604,492,429.53 365,411,097,358,592,000.00 Agustus 8 22,845,663,820.00 22,246,603,655.26 21,832,795,421.49 22,660,411,889.03 103,452,058.44 22,556,207,677.86 289,456,142.14 83,784,858,223,589,600.00 September 9 22,927,399,070.00 22,382,762,738.21 21,942,788,884.83 22,822,736,591.58 109,993,463.34 22,763,863,947.47 163,535,122.53 26,743,736,300,205,500.00 Oktober 10 22,854,910,720.00 22,477,192,334.57 22,049,669,574.78 22,904,715,094.35 106,880,689.95 22,932,730,054.93 -77,819,334.93 6,055,848,888,344,940.00 Oktober 11 22,764,705,655.00 22,534,694,998.65 22,146,674,659.55 22,922,715,337.75 97,005,084.77 23,011,595,784.30 -246,890,129.30 60,954,735,945,595,200.00 Desember 12 22,819,191,990.00 22,591,594,396.92 22,235,658,607.03 22,947,530,186.82 88,983,947.47 23,019,720,422.53 -200,528,432.53 40,211,652,251,619,500.00 2010 Januari 13 22,977,014,134.00 22,668,678,344.34 22,322,262,554.49 23,015,094,134.19 86,603,947.46 23,036,514,134.29 -59,500,000.29 3,540,250,034,624,960.00 Februari 14 22,942,268,240.00 22,723,396,323.47 22,402,489,308.28 23,044,303,338.66 80,226,753.80 23,101,698,081.65 -159,429,841.65 25,417,874,408,049,500.00 Maret 15 23,444,261,325.00 22,867,569,323.78 22,495,505,311.38 23,239,633,336.17 93,016,003.10 23,124,530,092.45 319,731,232.55 102,228,061,067,112,000.00 April 16 23,821,534,330.00 23,058,362,325.02 22,608,076,714.11 23,508,647,935.93 112,571,402.73 23,332,649,339.27 488,884,990.73 239,008,534,163,936,000.00 Mei 17 24,200,283,345.00 23,286,746,529.02 22,743,810,677.09 23,829,682,380.94 135,733,962.98 23,621,219,338.66 579,064,006.34 335,315,123,440,286,000.00 Juni 18 24,451,483,354.00 23,519,693,894.01 22,898,987,320.48 24,140,400,467.55 155,176,643.38 23,965,416,343.92 486,067,010.08 236,261,138,285,539,000.00 Juli 19 24,403,585,445.00 23,696,472,204.21 23,058,484,297.22 24,334,460,111.20 159,496,976.75 24,295,577,110.93 108,008,334.07 11,665,800,227,538,400.00 Agustus 20 24,272,090,440.00 23,811,595,851.37 23,209,106,608.05 24,414,085,094.68 150,622,310.83 24,493,957,087.95 -221,866,647.95 49,224,809,470,435,100.00 September 21 24,082,631,404.00 23,865,802,961.89 23,340,445,878.82 24,391,160,044.97 131,339,270.77 24,564,707,405.51 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,002,975,099.72 23,472,951,723.00 24,532,998,476.43 132,505,844.18 24,522,499,315.74 29,164,335.26 850,558,451,301,988.00 Oktober 23 24,612,143,420.00 24,124,808,763.77 23,603,323,131.15 24,646,294,396.39 130,371,408.15 24,665,504,320.61 -53,360,900.61 2,847,385,714,024,350.00 Desember 24 20,195,839,321.00 23,339,014,875.22 23,550,461,479.97 23,127,568,270.47 -52,861,651.19 24,776,665,804.55 -4,580,826,483.55 20,983,971,272,353,600,000.00 2011 Januari 25 18,547,485,425.00 22,380,708,985.17 23,316,510,981.01 21,444,906,989.34 -233,950,498.96 23,074,706,619.28 -4,527,221,194.28 20,495,731,741,956,400,000.00 Februari 26 22,317,670,660.00 22,368,101,320.14 23,126,829,048.83 21,609,373,591.44 -189,681,932.17 21,210,956,490.38 1,106,714,169.62 1,224,816,253,233,270,000.00 Maret 27 23,490,850,795.00 22,592,651,215.11 23,019,993,482.09 22,165,308,948.13 -106,835,566.74 21,419,691,659.27 2,071,159,135.73 4,289,700,165,514,950,000.00 April 28 23,401,919,900.00 22,754,504,952.09 22,966,895,776.09 22,542,114,128.09 -53,097,706.00 22,058,473,381.39 1,343,446,518.61 1,804,848,548,368,990,000.00 Mei 29 24,440,969,550.00 23,091,797,871.67 22,991,876,195.21 23,191,719,548.14 24,980,419.12 22,489,016,422.09 1,951,953,127.91 3,810,121,013,563,190,000.00 Juni 30 25,113,931,440.00 23,496,224,585.34 23,092,745,873.23 23,899,703,297.44 100,869,678.03 23,216,699,967.25 1,897,231,472.75 3,599,487,261,181,770,000.00 Juli 31 25,401,258,645.00 23,877,231,397.27 23,249,642,978.04 24,504,819,816.50 156,897,104.81 24,000,572,975.47 1,400,685,669.53 1,961,920,344,832,040,000.00 Agustus 32 25,321,323,110.00 24,166,049,739.82 23,432,924,330.40 24,899,175,149.24 183,281,352.36 24,661,716,921.31 659,606,188.69 435,080,324,162,046,000.00 September 33 25,080,556,135.00 24,348,951,018.85 23,616,129,668.09 25,081,772,369.62 183,205,337.69 25,082,456,501.59 -1,900,366.59 3,611,393,182,782.71 Oktober 34 25,109,569,925.00 24,501,074,800.08 23,793,118,694.49 25,209,030,905.68 176,989,026.40 25,264,977,707.31 -155,407,782.31 24,151,578,802,572,100.00 Oktober 35 25,282,275,715.00 24,657,314,983.07 23,965,957,952.20 25,348,672,013.93 172,839,257.72 25,386,019,932.08 -103,744,217.08 10,762,862,577,050,200.00 Desember 36 25,569,779,015.00 24,839,807,789.45 24,140,727,919.65 25,538,887,659.25 174,769,967.45 25,521,511,271.65 48,267,743.35 2,329,775,048,518,180.00 SE 4,712,089,880.73 SSE 60,915,304,961,002,700,000.00 M SE 1,791,626,616,500,080,000.00 Tabel 4.3 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,2 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,3 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,3 21.548.149.420,00 + 1-0,3 21.473.831.050,00 = 21.496.126.561,00 Maret 2009 = 0,3 21.789.329.725,00 + 1-0,3 21.496.126.561,00 = 21.584.087.510,20 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,3 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,3 21.496.126.561,00 + 1-0,3 21.473.831.050,00 = 21.480.519.703,30 Maret 2009 = 0,3 21.584.087.510,20 + 1-0,3 21.480.519.703,30 = 21.511.590.045,37 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.496.126.561,00 – 21.480.519.703,30 = 21.511.733.418,70 Maret 2009 = 221.584.087.510,20 - 21.511.590.045,37 = 21.656.584.975,03 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,3 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.496.126.561,00 – 21.480.519.703,30 = 6.688.653,30 Maret 2009 = , , 21.584.087.510,20 - 21.511.590.045,37 = 31.070.342,07 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.511.733.418,70 + 6.688.653,30 1 = 21.518.422.072,00 F April 2009 untuk m = 1 = 21.656.584.975,03 + 31.070.342,07 1 = 21.687.655.317,10 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,496,126,561.00 21,480,519,703.30 21,511,733,418.70 6,688,653.30 Maret 3 21,789,329,725.00 21,584,087,510.20 21,511,590,045.37 21,656,584,975.03 31,070,342.07 21,518,422,072.00 270,907,653.00 73,390,956,453,968,400.00 April 4 22,005,291,800.00 21,710,448,797.14 21,571,247,670.90 21,849,649,923.38 59,657,625.53 21,687,655,317.10 317,636,482.90 100,892,935,269,083,000.00 Mei 5 22,264,141,990.00 21,876,556,755.00 21,662,840,396.13 22,090,273,113.87 91,592,725.23 21,909,307,548.91 354,834,441.09 125,907,480,583,647,000.00 Juni 6 22,481,546,105.00 22,058,053,560.00 21,781,404,345.29 22,334,702,774.71 118,563,949.16 22,181,865,839.10 299,680,265.90 89,808,261,772,883,900.00 Juli 7 22,851,209,020.00 22,296,000,198.00 21,935,783,101.10 22,656,217,294.89 154,378,755.81 22,453,266,723.87 397,942,296.13 158,358,071,051,516,000.00 Agustus 8 22,845,663,820.00 22,460,899,284.60 22,093,317,956.15 22,828,480,613.05 157,534,855.05 22,810,596,050.71 35,067,769.29 1,229,748,443,158,930.00 September 9 22,927,399,070.00 22,600,849,220.22 22,245,577,335.37 22,956,121,105.07 152,259,379.22 22,986,015,468.10 -58,616,398.10 3,435,882,125,686,670.00 Oktober 10 22,854,910,720.00 22,677,067,670.15 22,375,024,435.81 22,979,110,904.50 129,447,100.43 23,108,380,484.29 -253,469,764.29 64,246,921,407,726,000.00 Oktober 11 22,764,705,655.00 22,703,359,065.61 22,473,524,824.75 22,933,193,306.47 98,500,388.94 23,108,558,004.94 -343,852,349.94 118,234,438,555,867,000.00 Desember 12 22,819,191,990.00 22,738,108,942.93 22,552,900,060.20 22,923,317,825.65 79,375,235.45 23,031,693,695.41 -212,501,705.41 45,156,974,801,498,500.00 2010 Januari 13 22,977,014,134.00 22,809,780,500.25 22,629,964,192.21 22,989,596,808.28 77,064,132.01 23,002,693,061.10 -25,678,927.10 659,407,297,194,526.00 Februari 14 22,942,268,240.00 22,849,526,822.17 22,695,832,981.20 23,003,220,663.14 65,868,788.99 23,066,660,940.30 -124,392,700.29 15,473,543,886,673,600.00 Maret 15 23,444,261,325.00 23,027,947,173.02 22,795,467,238.75 23,260,427,107.29 99,634,257.55 23,069,089,452.13 375,171,872.87 140,753,934,191,154,000.00 April 16 23,821,534,330.00 23,266,023,320.12 22,936,634,063.16 23,595,412,577.07 141,166,824.41 23,360,061,364.84 461,472,965.16 212,957,297,573,101,000.00 Mei 17 24,200,283,345.00 23,546,301,327.58 23,119,534,242.48 23,973,068,412.68 182,900,179.33 23,736,579,401.48 463,703,943.52 215,021,347,234,206,000.00 Juni 18 24,451,483,354.00 23,817,855,935.51 23,329,030,750.39 24,306,681,120.62 209,496,507.91 24,155,968,592.00 295,514,762.00 87,328,974,558,223,400.00 Juli 19 24,403,585,445.00 23,993,574,788.35 23,528,393,961.78 24,458,755,614.93 199,363,211.39 24,516,177,628.53 -112,592,183.53 12,676,999,791,571,900.00 Agustus 20 24,272,090,440.00 24,077,129,483.85 23,693,014,618.40 24,461,244,349.30 164,620,656.62 24,658,118,826.32 -386,028,386.32 149,017,915,042,979,000.00 September 21 24,082,631,404.00 24,078,780,059.89 23,808,744,250.85 24,348,815,868.94 115,729,632.45 24,625,865,005.92 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,220,645,137.23 23,932,314,516.76 24,508,975,757.69 123,570,265.91 24,464,545,501.39 87,118,149.61 7,589,571,992,033,410.00 Oktober 23 24,612,143,420.00 24,338,094,622.06 24,054,048,548.35 24,622,140,695.77 121,734,031.59 24,632,546,023.60 -20,402,603.60 416,266,233,766,231.00 Desember 24 20,195,839,321.00 23,095,418,031.74 23,766,459,393.37 22,424,376,670.11 -287,589,154.98 24,743,874,727.35 -4,548,035,406.35 20,684,626,057,451,200,000.00 2011 Januari 25 18,547,485,425.00 21,731,038,249.72 23,155,833,050.27 20,306,243,449.16 -610,626,343.09 22,136,787,515.13 -3,589,302,090.13 12,883,089,494,215,500,000.00 Februari 26 22,317,670,660.00 21,907,027,972.80 22,781,191,527.03 21,032,864,418.57 -374,641,523.24 19,695,617,106.07 2,622,053,553.93 6,875,164,839,680,990,000.00 Maret 27 23,490,850,795.00 22,382,174,819.46 22,661,486,514.76 22,102,863,124.16 -119,705,012.27 20,658,222,895.33 2,832,627,899.67 8,023,780,817,972,160,000.00 April 28 23,401,919,900.00 22,688,098,343.62 22,669,470,063.42 22,706,726,623.83 7,983,548.66 21,983,158,111.89 1,418,761,788.11 2,012,885,011,394,830,000.00 Mei 29 24,440,969,550.00 23,213,959,705.54 22,832,816,956.05 23,595,102,455.02 163,346,892.64 22,714,710,172.49 1,726,259,377.51 2,979,971,438,455,220,000.00 Juni 30 25,113,931,440.00 23,783,951,225.88 23,118,157,237.00 24,449,745,214.75 285,340,280.95 23,758,449,347.65 1,355,482,092.35 1,837,331,702,673,020,000.00 Juli 31 25,401,258,645.00 24,269,143,451.61 23,463,453,101.38 25,074,833,801.84 345,295,864.38 24,735,085,495.70 666,173,149.30 443,786,664,853,224,000.00 Agustus 32 25,321,323,110.00 24,584,797,349.13 23,799,856,375.71 25,369,738,322.55 336,403,274.32 25,420,129,666.22 -98,806,556.22 9,762,735,552,996,290.00 September 33 25,080,556,135.00 24,733,524,984.89 24,079,956,958.46 25,387,093,011.32 280,100,582.75 25,706,141,596.87 -625,585,461.87 391,357,170,107,462,000.00 Oktober 34 25,109,569,925.00 24,846,338,466.92 24,309,871,411.00 25,382,805,522.85 229,914,452.54 25,667,193,594.07 -557,623,669.07 310,944,156,310,156,000.00 Oktober 35 25,282,275,715.00 24,977,119,641.35 24,510,045,880.10 25,444,193,402.59 200,174,469.10 25,612,719,975.38 -330,444,260.38 109,193,409,220,620,000.00 Desember 36 25,569,779,015.00 25,154,917,453.44 24,703,507,352.11 25,606,327,554.78 193,461,472.00 25,644,367,871.69 -74,588,856.69 5,563,497,542,579,510.00 SE 2,553,570,206.00 SSE 58,194,228,132,410,500,000.00 MSE 1,711,594,945,070,900,000.00 Tabel 4.4 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,3 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,4 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,4 21.548.149.420,00 + 1-0,4 21.473.831.050,00 = 21.503.558.398,00 Maret 2009 = 0,4 21.789.329.725,00 + 1-0,4 21.503.558.398,00 = 21.617.866.928,80 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,4 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,4 21.503.558.398,00 + 1-0,4 21.473.831.050,00 = 21.485.721.989,20 Maret 2009 = 0,4 21.617.866.928,80+1-0,4 21.485.721.989,20 = 21.538.579.965,04 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.503.558.398,00 – 21.485.721.989,20 = 21.521.394.806,80 Maret 2009 = 221.617.866.928,80 - 21.538.579.965,04 = 21.697.153.892,56 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,4 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.503.558.398,00 – 21.485.721.989,20 = 11.890.939,20 Maret 2009 = , , 21.617.866.928,80 - 21.538.579.965,04 = 52.857.975,84 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.521.394.806,80 + 11.890.939,20 1 = 21.533.285.746,00 F April 2009 untuk m = 1 = 21.697.153.892,56 + 52.857.975,84 1 = 21.750.011.868,40 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,503,558,398.00 21,485,721,989.20 21,521,394,806.80 11,890,939.20 Maret 3 21,789,329,725.00 21,617,866,928.80 21,538,579,965.04 21,697,153,892.56 52,857,975.84 21,533,285,746.00 256,043,979.00 65,558,519,182,152,400.00 April 4 22,005,291,800.00 21,772,836,877.28 21,632,282,729.94 21,913,391,024.62 93,702,764.90 21,750,011,868.40 255,279,931.60 65,167,843,477,701,800.00 Mei 5 22,264,141,990.00 21,969,358,922.37 21,767,113,206.91 22,171,604,637.83 134,830,476.97 22,007,093,789.52 257,048,200.48 66,073,777,370,008,000.00 Juni 6 22,481,546,105.00 22,174,233,795.42 21,929,961,442.31 22,418,506,148.53 162,848,235.40 22,306,435,114.80 175,110,990.20 30,663,858,888,827,400.00 Juli 7 22,851,209,020.00 22,445,023,885.25 22,135,986,419.49 22,754,061,351.02 206,024,977.18 22,581,354,383.93 269,854,636.07 72,821,524,606,960,800.00 Agustus 8 22,845,663,820.00 22,605,279,859.15 22,323,703,795.35 22,886,855,922.95 187,717,375.86 22,960,086,328.19 -114,422,508.19 13,092,510,380,802,000.00 September 9 22,927,399,070.00 22,734,127,543.49 22,487,873,294.61 22,980,381,792.37 164,169,499.25 23,074,573,298.81 -147,174,228.81 21,660,253,626,943,700.00 Oktober 10 22,854,910,720.00 22,782,440,814.09 22,605,700,302.40 22,959,181,325.79 117,827,007.79 23,144,551,291.63 -289,640,571.63 83,891,660,732,814,700.00 Oktober 11 22,764,705,655.00 22,775,346,750.46 22,673,558,881.62 22,877,134,619.29 67,858,579.22 23,077,008,333.58 -312,302,678.58 97,532,963,048,408,300.00 Desember 12 22,819,191,990.00 22,792,884,846.27 22,721,289,267.48 22,864,480,425.06 47,730,385.86 22,944,993,198.51 -125,801,208.51 15,825,944,062,661,500.00 2010 Januari 13 22,977,014,134.00 22,866,536,561.36 22,779,388,185.04 22,953,684,937.69 58,098,917.55 22,912,210,810.92 64,803,323.08 4,199,470,681,754,760.00 Februari 14 22,942,268,240.00 22,896,829,232.82 22,826,364,604.15 22,967,293,861.49 46,976,419.11 23,011,783,855.24 -69,515,615.24 4,832,420,762,821,250.00 Maret 15 23,444,261,325.00 23,115,802,069.69 22,942,139,590.37 23,289,464,549.02 115,774,986.22 23,014,270,280.60 429,991,044.40 184,892,298,263,407,000.00 April 16 23,821,534,330.00 23,398,094,973.81 23,124,521,743.75 23,671,668,203.88 182,382,153.38 23,405,239,535.23 416,294,794.77 173,301,356,150,021,000.00 Mei 17 24,200,283,345.00 23,718,970,322.29 23,362,301,175.16 24,075,639,469.41 237,779,431.42 23,854,050,357.26 346,232,987.74 119,877,281,797,028,000.00 Juni 18 24,451,483,354.00 24,011,975,534.97 23,622,170,919.09 24,401,780,150.86 259,869,743.92 24,313,418,900.83 138,064,453.17 19,061,793,228,541,800.00 Juli 19 24,403,585,445.00 24,168,619,498.98 23,840,750,351.05 24,496,488,646.92 218,579,431.96 24,661,649,894.78 -258,064,449.78 66,597,260,242,192,900.00 Agustus 20 24,272,090,440.00 24,210,007,875.39 23,988,453,360.78 24,431,562,390.00 147,703,009.74 24,715,068,078.88 -442,977,638.88 196,229,188,548,529,000.00 September 21 24,082,631,404.00 24,159,057,286.83 24,056,694,931.20 24,261,419,642.46 68,241,570.42 24,579,265,399.74 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,316,099,832.50 24,160,456,891.72 24,471,742,773.28 103,761,960.52 24,329,661,212.88 222,002,438.12 49,285,082,529,081,400.00 Oktober 23 24,612,143,420.00 24,434,517,267.50 24,270,081,042.03 24,598,953,492.97 109,624,150.31 24,575,504,733.80 36,638,686.20 1,342,393,326,667,300.00 Desember 24 20,195,839,321.00 22,739,046,088.90 23,657,667,060.78 21,820,425,117.02 -612,413,981.25 24,708,577,643.28 -4,512,738,322.28 20,364,807,165,357,400,000.00 2011 Januari 25 18,547,485,425.00 21,062,421,823.34 22,619,568,965.80 19,505,274,680.88 -1,038,098,094.98 21,208,011,135.77 -2,660,525,710.77 7,078,397,057,650,820,000.00 Februari 26 22,317,670,660.00 21,564,521,358.00 22,197,549,922.68 20,931,492,793.32 -422,019,043.12 18,467,176,585.90 3,850,494,074.10 14,826,304,614,679,500,000.00 Maret 27 23,490,850,795.00 22,335,053,132.80 22,252,551,206.73 22,417,555,058.87 55,001,284.05 20,509,473,750.20 2,981,377,044.80 8,888,609,083,236,970,000.00 April 28 23,401,919,900.00 22,761,799,839.68 22,456,250,659.91 23,067,349,019.45 203,699,453.18 22,472,556,342.92 929,363,557.08 863,716,621,227,054,000.00 Mei 29 24,440,969,550.00 23,433,467,723.81 22,847,137,485.47 24,019,797,962.15 390,886,825.56 23,271,048,472.63 1,169,921,077.37 1,368,715,327,271,190,000.00 Juni 30 25,113,931,440.00 24,105,653,210.29 23,350,543,775.40 24,860,762,645.17 503,406,289.93 24,410,684,787.71 703,246,652.29 494,555,853,962,314,000.00 Juli 31 25,401,258,645.00 24,623,895,384.17 23,859,884,418.91 25,387,906,349.44 509,340,643.51 25,364,168,935.10 37,089,709.90 1,375,646,580,449,580.00 Agustus 32 25,321,323,110.00 24,902,866,474.50 24,277,077,241.14 25,528,655,707.86 417,192,822.24 25,897,246,992.95 -575,923,882.95 331,688,318,947,601,000.00 September 33 25,080,556,135.00 24,973,942,338.70 24,555,823,280.17 25,392,061,397.24 278,746,039.02 25,945,848,530.10 -865,292,395.10 748,730,929,016,367,000.00 Oktober 34 25,109,569,925.00 25,028,193,373.22 24,744,771,317.39 25,311,615,429.05 188,948,037.22 25,670,807,436.26 -561,237,511.26 314,987,544,043,505,000.00 Oktober 35 25,282,275,715.00 25,129,826,309.93 24,898,793,314.41 25,360,859,305.46 154,021,997.02 25,500,563,466.27 -218,287,751.27 47,649,542,356,423,800.00 Desember 36 25,569,779,015.00 25,305,807,391.96 25,061,598,945.43 25,550,015,838.49 162,805,631.02 25,514,881,302.48 54,897,712.52 3,013,758,840,342,010.00 SE 1,374,933,882.58 SSE 56,688,673,072,791,900,000.00 MSE 1,667,313,913,905,640,000.00 Tabel 4.5 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,4 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,5 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,5 21.548.149.420,00 + 1-0,5 21.473.831.050,00 = 21.510.990.235,00 Maret 2009 = 0,5 21.789.329.725,00 + 1-0,5 21.510.990.235,00 = 21.650.159.980,00 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,5 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,5 21.510.990.235,00 + 1-0,5 21.473.831.050,00 = 21.492.410.642,50 Maret 2009 = 0,5 21.650.159.980,00 + 1-0,5 21.492.410.642,50 = 21.571.285.311,25 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.510.990.235,00 – 21.492.410.642,50 = 21.529.569.827,50 Maret 2009 = 221.650.159.980,00 - 21.571.285.311,25 = 21.729.034.648,75 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,5 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.510.990.235,00 – 21.492.410.642,50 = 18.579.592,50 Maret 2009 = , , 21.650.159.980,00 - 21.571.285.311,25 = 78.874.668,75 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.529.569.827,50 + 18.579.592,50 1 = 21.548.149.420,00 F April 2009 untuk m = 1 = 21.729.034.648,75 + 78.874.668,75 1 = 21.807.909.317,50 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,510,990,235.00 21,492,410,642.50 21,529,569,827.50 18,579,592.50 Maret 3 21,789,329,725.00 21,650,159,980.00 21,571,285,311.25 21,729,034,648.75 78,874,668.75 21,548,149,420.00 241,180,305.00 58,167,939,519,893,000.00 April 4 22,005,291,800.00 21,827,725,890.00 21,699,505,600.63 21,955,946,179.38 128,220,289.38 21,807,909,317.50 197,382,482.50 38,959,844,397,862,800.00 Mei 5 22,264,141,990.00 22,045,933,940.00 21,872,719,770.31 22,219,148,109.69 173,214,169.69 22,084,166,468.75 179,975,521.25 32,391,188,249,209,200.00 Juni 6 22,481,546,105.00 22,263,740,022.50 22,068,229,896.41 22,459,250,148.59 195,510,126.09 22,392,362,279.38 89,183,825.63 7,953,754,753,110,410.00 Juli 7 22,851,209,020.00 22,557,474,521.25 22,312,852,208.83 22,802,096,833.67 244,622,312.42 22,654,760,274.69 196,448,745.31 38,592,109,534,855,500.00 Agustus 8 22,845,663,820.00 22,701,569,170.63 22,507,210,689.73 22,895,927,651.52 194,358,480.90 23,046,719,146.09 -201,055,326.09 40,423,244,150,664,200.00 September 9 22,927,399,070.00 22,814,484,120.31 22,660,847,405.02 22,968,120,835.61 153,636,715.29 23,090,286,132.42 -162,887,062.42 26,532,195,104,427,800.00 Oktober 10 22,854,910,720.00 22,834,697,420.16 22,747,772,412.59 22,921,622,427.72 86,925,007.57 23,121,757,550.90 -266,846,830.90 71,207,231,160,539,300.00 Oktober 11 22,764,705,655.00 22,799,701,537.58 22,773,736,975.08 22,825,666,100.07 25,964,562.50 23,008,547,435.29 -243,841,780.29 59,458,813,816,444,400.00 Desember 12 22,819,191,990.00 22,809,446,763.79 22,791,591,869.44 22,827,301,658.14 17,854,894.35 22,851,630,662.57 -32,438,672.57 1,052,267,477,997,230.00 2010 Januari 13 22,977,014,134.00 22,893,230,448.89 22,842,411,159.17 22,944,049,738.62 50,819,289.73 22,845,156,552.50 131,857,581.50 17,386,421,800,316,800.00 Februari 14 22,942,268,240.00 22,917,749,344.45 22,880,080,251.81 22,955,418,437.09 37,669,092.64 22,994,869,028.35 -52,600,788.35 2,766,842,935,359,980.00 Maret 15 23,444,261,325.00 23,181,005,334.72 23,030,542,793.27 23,331,467,876.18 150,462,541.46 22,993,087,529.73 451,173,795.27 203,557,793,539,014,000.00 April 16 23,821,534,330.00 23,501,269,832.36 23,265,906,312.81 23,736,633,351.91 235,363,519.55 23,481,930,417.64 339,603,912.36 115,330,817,289,545,000.00 Mei 17 24,200,283,345.00 23,850,776,588.68 23,558,341,450.75 24,143,211,726.61 292,435,137.93 23,971,996,871.46 228,286,473.54 52,114,714,001,932,200.00 Juni 18 24,451,483,354.00 24,151,129,971.34 23,854,735,711.04 24,447,524,231.64 296,394,260.30 24,435,646,864.55 15,836,489.45 250,794,398,149,644.00 Juli 19 24,403,585,445.00 24,277,357,708.17 24,066,046,709.61 24,488,668,706.73 211,310,998.56 24,743,918,491.93 -340,333,046.93 115,826,582,835,218,000.00 Agustus 20 24,272,090,440.00 24,274,724,074.09 24,170,385,391.85 24,379,062,756.32 104,338,682.24 24,699,979,705.30 -427,889,265.30 183,089,223,356,110,000.00 September 21 24,082,631,404.00 24,178,677,739.04 24,174,531,565.44 24,182,823,912.64 4,146,173.60 24,483,401,438.56 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,365,170,695.02 24,269,851,130.23 24,460,490,259.81 95,319,564.79 24,186,970,086.24 364,693,564.76 133,001,396,178,048,000.00 Oktober 23 24,612,143,420.00 24,488,657,057.51 24,379,254,093.87 24,598,060,021.15 109,402,963.64 24,555,809,824.60 56,333,595.40 3,173,473,970,888,780.00 Desember 24 20,195,839,321.00 22,342,248,189.26 23,360,751,141.56 21,323,745,236.95 -1,018,502,952.31 24,707,462,984.79 -4,511,623,663.79 20,354,748,083,656,200,000.00 2011 Januari 25 18,547,485,425.00 20,444,866,807.13 21,902,808,974.35 18,986,924,639.91 -1,457,942,167.22 20,305,242,284.64 -1,757,756,859.64 3,089,709,177,607,660,000.00 Februari 26 22,317,670,660.00 21,381,268,733.56 21,642,038,853.95 21,120,498,613.17 -260,770,120.39 17,528,982,472.69 4,788,688,187.31 22,931,534,555,265,100,000.00 Maret 27 23,490,850,795.00 22,436,059,764.28 22,039,049,309.12 22,833,070,219.45 397,010,455.16 20,859,728,492.78 2,631,122,302.22 6,922,804,569,228,600,000.00 April 28 23,401,919,900.00 22,918,989,832.14 22,479,019,570.63 23,358,960,093.65 439,970,261.51 23,230,080,674.61 171,839,225.39 29,528,719,382,936,500.00 Mei 29 24,440,969,550.00 23,679,979,691.07 23,079,499,630.85 24,280,459,751.29 600,480,060.22 23,798,930,355.16 642,039,194.84 412,214,327,706,162,000.00 Juni 30 25,113,931,440.00 24,396,955,565.54 23,738,227,598.19 25,055,683,532.88 658,727,967.34 24,880,939,811.51 232,991,628.49 54,285,098,945,802,600.00 Juli 31 25,401,258,645.00 24,899,107,105.27 24,318,667,351.73 25,479,546,858.81 580,439,753.54 25,714,411,500.22 -313,152,855.22 98,064,710,732,701,900.00 Agustus 32 25,321,323,110.00 25,110,215,107.63 24,714,441,229.68 25,505,988,985.59 395,773,877.95 26,059,986,612.34 -738,663,502.34 545,623,769,693,028,000.00 September 33 25,080,556,135.00 25,095,385,621.32 24,904,913,425.50 25,285,857,817.13 190,472,195.82 25,901,762,863.54 -821,206,728.54 674,380,490,995,248,000.00 Oktober 34 25,109,569,925.00 25,102,477,773.16 25,003,695,599.33 25,201,259,946.99 98,782,173.83 25,476,330,012.95 -366,760,087.95 134,512,962,114,441,000.00 November 35 25,282,275,715.00 25,192,376,744.08 25,098,036,171.70 25,286,717,316.45 94,340,572.38 25,300,042,120.82 -17,766,405.82 315,645,175,670,916.00 Desember 36 25,569,779,015.00 25,381,077,879.54 25,239,557,025.62 25,522,598,733.46 141,520,853.92 25,381,057,888.83 188,721,126.17 35,615,663,463,058,100.00 SE 827,618,143.19 SSE 56,488,788,631,150,800,000.00 M SE 1,661,434,959,739,730,000.00 a = 0,5 Tabel 4.6 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,6 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,6 21.548.149.420,00 + 1-0,6 21.473.831.050,00 = 21.518.422.072,00 Maret 2009 = 0,6 21.789.329.725,00 + 1-0,6 21.518.422.072,00 =21.680.966.663,80 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,6 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,6 21.518.422.072,00 + 1-0,6 21.473.831.050,00 = 21.500.585.663,20 Maret 2009 = 0,6 21.680.966.663,80 + 1-0,6 21.500.585.663,20 = 21.608.814.263,56 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.518.422.072,00 – 21.500.585.663,20 = 21.536.258.480,80 Maret 2009 = 221.680.966.663,80 - 21.608.814.263,56 = 21.753.119.064,04 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,6 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.518.422.072,00 – 21.500.585.663,20 = 26.754.613,20 Maret 2009 = , , 21.680.966.663,80 - 21.608.814.263,56 = 108.228.600,36 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.536.258.480,80 + 26.754.613,20 1 = 21.563.013.094,00 F April 2009 untuk m = 1 = 21.753.119.064,04 + 108.228.600,36 1 = 21.861.347.664,40 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,518,422,072.00 21,500,585,663.20 21,536,258,480.80 26,754,613.20 Maret 3 21,789,329,725.00 21,680,966,663.80 21,608,814,263.56 21,753,119,064.04 108,228,600.36 21,563,013,094.00 226,316,631.00 51,219,217,467,186,700.00 April 4 22,005,291,800.00 21,875,561,745.52 21,768,862,752.74 21,982,260,738.30 160,048,489.18 21,861,347,664.40 143,944,135.60 20,719,914,173,626,400.00 Mei 5 22,264,141,990.00 22,108,709,892.21 21,972,771,036.42 22,244,648,748.00 203,908,283.68 22,142,309,227.48 121,832,762.52 14,843,222,023,251,100.00 Juni 6 22,481,546,105.00 22,332,411,619.88 22,188,555,386.50 22,476,267,853.27 215,784,350.08 22,448,557,031.68 32,989,073.32 1,088,278,958,512,570.00 Juli 7 22,851,209,020.00 22,643,690,059.95 22,461,636,190.57 22,825,743,929.34 273,080,804.07 22,692,052,203.35 159,156,816.65 25,330,892,287,052,300.00 Agustus 8 22,845,663,820.00 22,764,874,315.98 22,643,579,065.82 22,886,169,566.15 181,942,875.25 23,098,824,733.41 -253,160,913.41 64,090,448,078,062,000.00 September 9 22,927,399,070.00 22,862,389,168.39 22,774,865,127.36 22,949,913,209.42 131,286,061.55 23,068,112,441.39 -140,713,371.39 19,800,252,888,397,200.00 Oktober 10 22,854,910,720.00 22,857,902,099.36 22,824,687,310.56 22,891,116,888.15 49,822,183.20 23,081,199,270.97 -226,288,550.97 51,206,508,299,130,900.00 Oktober 11 22,764,705,655.00 22,801,984,232.74 22,811,065,463.87 22,792,903,001.62 -13,621,846.69 22,940,939,071.35 -176,233,416.35 31,058,217,038,963,300.00 Desember 12 22,819,191,990.00 22,812,308,887.10 22,811,811,517.81 22,812,806,256.39 746,053.94 22,779,281,154.93 39,910,835.07 1,592,874,756,268,510.00 2010 Januari 13 22,977,014,134.00 22,911,132,035.24 22,871,403,828.27 22,950,860,242.21 59,592,310.46 22,813,552,310.32 163,461,823.68 26,719,767,799,192,700.00 Februari 14 22,942,268,240.00 22,929,813,758.10 22,906,449,786.16 22,953,177,730.03 35,045,957.90 23,010,452,552.67 -68,184,312.67 4,649,100,494,509,480.00 Maret 15 23,444,261,325.00 23,238,482,298.24 23,105,669,293.41 23,371,295,303.07 199,219,507.24 22,988,223,687.93 456,037,637.07 207,970,326,428,613,000.00 April 16 23,821,534,330.00 23,588,313,517.30 23,395,255,827.74 23,781,371,206.85 289,586,534.33 23,570,514,810.31 251,019,519.69 63,010,799,263,980,400.00 Mei 17 24,200,283,345.00 23,955,495,413.92 23,731,399,579.45 24,179,591,248.39 336,143,751.71 24,070,957,741.18 129,325,603.82 16,725,111,802,839,200.00 Juni 18 24,451,483,354.00 24,253,088,177.97 24,044,412,738.56 24,461,763,617.38 313,013,159.11 24,515,735,000.10 -64,251,646.10 4,128,274,026,006,990.00 Juli 19 24,403,585,445.00 24,343,386,538.19 24,223,797,018.34 24,462,976,058.04 179,384,279.78 24,774,776,776.49 -371,191,331.49 137,783,004,571,397,000.00 Agustus 20 24,272,090,440.00 24,300,608,879.27 24,269,884,134.90 24,331,333,623.65 46,087,116.56 24,642,360,337.81 -370,269,897.81 137,099,797,227,641,000.00 September 21 24,082,631,404.00 24,169,822,394.11 24,209,847,090.43 24,129,797,697.79 -60,037,044.47 24,377,420,740.21 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,398,927,148.24 24,323,295,125.12 24,474,559,171.37 113,448,034.69 24,069,760,653.32 481,902,997.68 232,230,499,172,371,000.00 Oktober 23 24,612,143,420.00 24,526,856,911.30 24,445,432,196.83 24,608,281,625.77 122,137,071.71 24,588,007,206.06 24,136,213.94 582,556,823,246,161.00 Desember 24 20,195,839,321.00 21,928,246,357.12 22,935,120,693.00 20,921,372,021.24 -1,510,311,503.82 24,730,418,697.48 -4,534,579,376.48 20,562,410,121,584,500,000.00 2011 Januari 25 18,547,485,425.00 19,899,789,797.85 21,113,922,155.91 18,685,657,439.79 -1,821,198,537.09 19,411,060,517.41 -863,575,092.41 745,761,940,235,881,000.00 Februari 26 22,317,670,660.00 21,350,518,315.14 21,255,879,851.45 21,445,156,778.83 141,957,695.54 16,864,458,902.69 5,453,211,757.31 29,737,518,470,023,400,000.00 Maret 27 23,490,850,795.00 22,634,717,803.06 22,083,182,622.41 23,186,252,983.70 827,302,770.97 21,587,114,474.37 1,903,736,320.63 3,624,211,978,489,980,000.00 April 28 23,401,919,900.00 23,095,039,061.22 22,690,296,485.70 23,499,781,636.75 607,113,863.29 24,013,555,754.66 -611,635,854.66 374,098,418,710,736,000.00 Mei 29 24,440,969,550.00 23,902,597,354.49 23,417,677,006.97 24,387,517,702.01 727,380,521.27 24,106,895,500.03 334,074,049.97 111,605,470,861,835,000.00 Juni 30 25,113,931,440.00 24,629,397,805.80 24,144,709,486.27 25,114,086,125.32 727,032,479.29 25,114,898,223.28 -966,783.28 934,669,909,644.34 Juli 31 25,401,258,645.00 25,092,514,309.32 24,713,392,380.10 25,471,636,238.54 568,682,893.83 25,841,118,604.62 -439,859,959.62 193,476,784,075,588,000.00 Agustus 32 25,321,323,110.00 25,229,799,589.73 25,023,236,705.88 25,436,362,473.58 309,844,325.78 26,040,319,132.37 -718,996,022.37 516,955,280,183,979,000.00 September 33 25,080,556,135.00 25,140,253,516.89 25,093,446,792.48 25,187,060,241.30 70,210,086.61 25,746,206,799.36 -665,650,664.36 443,090,806,959,040,000.00 Oktober 34 25,109,569,925.00 25,121,843,361.76 25,110,484,734.05 25,133,201,989.47 17,037,941.56 25,257,270,327.91 -147,700,402.91 21,815,409,018,731,700.00 Oktober 35 25,282,275,715.00 25,218,102,773.70 25,175,055,557.84 25,261,149,989.56 64,570,823.79 25,150,239,931.03 132,035,783.97 17,433,448,249,091,600.00 Desember 36 25,569,779,015.00 25,429,108,518.48 25,327,487,334.22 25,530,729,702.74 152,431,776.38 25,325,720,813.36 244,058,201.64 59,564,405,789,024,200.00 SE 578,975,630.24 SSE 57,524,006,741,146,600,000.00 MSE 1,691,882,551,210,190,000.00 Tabel 4.7 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,6 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,7 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,7 21.548.149.420,00 + 1-0,7 21.473.831.050,00 = 21.525.853.909,00 Maret 2009 = 0,7 21.789.329.725,00 + 1-0,7 21.525.853.909,00 = 21.710.286.980,20 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,7 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,7 21.525.853.909,00 + 1-0,7 21.473.831.050,00 = 21.510.247.051,30 Maret 2009 = 0,7 21.710.286.980,20 + 1-0,7 21.510.247.051,30 = 21.650.275.001,53 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.525.853.909,00 – 21.510.247.051,30 = 21.541.460.766,70 Maret 2009 = 221.710.286.980,20 - 21.650.275.001,53 = 21.770.298.958,87 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,7 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.525.853.909,00 – 21.510.247.051,30 = 36.416.001,30 Maret 2009 = , , 21.710.286.980,20 - 21.650.275.001,53 = 140.027.950,23 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.541.460.766,70 + 36.416.001,30 1 = 21.577.876.768,00 F April 2009 untuk m = 1 = 21.770.298.958,87 + 140.027.950,23 1 =21.910.326.909,10 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,525,853,909.00 21,510,247,051.30 21,541,460,766.70 36,416,001.30 Maret 3 21,789,329,725.00 21,710,286,980.20 21,650,275,001.53 21,770,298,958.87 140,027,950.23 21,577,876,768.00 211,452,957.00 44,712,353,024,042,200.00 April 4 22,005,291,800.00 21,916,790,354.06 21,836,835,748.30 21,996,744,959.82 186,560,746.77 21,910,326,909.10 94,964,890.90 9,018,330,503,650,640.00 Mei 5 22,264,141,990.00 22,159,936,499.22 22,063,006,273.94 22,256,866,724.49 226,170,525.64 22,183,305,706.59 80,836,283.41 6,534,504,715,540,580.00 Juni 6 22,481,546,105.00 22,385,063,223.27 22,288,446,138.47 22,481,680,308.06 225,439,864.53 22,483,037,250.14 -1,491,145.14 2,223,513,813,640.54 Juli 7 22,851,209,020.00 22,711,365,280.98 22,584,489,538.23 22,838,241,023.73 296,043,399.76 22,707,120,172.59 144,088,847.41 20,761,595,948,545,700.00 Agustus 8 22,845,663,820.00 22,805,374,258.29 22,739,108,842.27 22,871,639,674.31 154,619,304.05 23,134,284,423.49 -288,620,603.49 83,301,852,759,274,100.00 September 9 22,927,399,070.00 22,890,791,626.49 22,845,286,791.22 22,936,296,461.75 106,177,948.95 23,026,258,978.36 -98,859,908.36 9,773,281,481,235,080.00 Oktober 10 22,854,910,720.00 22,865,674,991.95 22,859,558,531.73 22,871,791,452.16 14,271,740.51 23,042,474,410.70 -187,563,690.70 35,180,138,070,024,400.00 Oktober 11 22,764,705,655.00 22,794,996,456.08 22,814,365,078.78 22,775,627,833.39 -45,193,452.95 22,886,063,192.67 -121,357,537.67 14,727,651,949,107,400.00 Desember 12 22,819,191,990.00 22,811,933,329.83 22,812,662,854.51 22,811,203,805.14 -1,702,224.27 22,730,434,380.44 88,757,609.56 7,877,913,255,121,880.00 2010 Januari 13 22,977,014,134.00 22,927,489,892.75 22,893,041,781.28 22,961,938,004.22 80,378,926.77 22,809,501,580.87 167,512,553.13 28,060,455,455,225,300.00 Februari 14 22,942,268,240.00 22,937,834,735.82 22,924,396,849.46 22,951,272,622.19 31,355,068.18 23,042,316,930.98 -100,048,690.98 10,009,740,567,651,100.00 Maret 15 23,444,261,325.00 23,292,333,348.25 23,181,952,398.61 23,402,714,297.88 257,555,549.15 22,982,627,690.37 461,633,634.63 213,105,612,619,888,000.00 April 16 23,821,534,330.00 23,662,774,035.47 23,518,527,544.42 23,807,020,526.53 336,575,145.80 23,660,269,847.03 161,264,482.97 26,006,233,466,094,300.00 Mei 17 24,200,283,345.00 24,039,030,552.14 23,882,879,649.82 24,195,181,454.46 364,352,105.41 24,143,595,672.34 56,687,672.66 3,213,492,231,914,360.00 Juni 18 24,451,483,354.00 24,327,747,513.44 24,194,287,154.36 24,461,207,872.53 311,407,504.53 24,559,533,559.87 -108,050,205.87 11,674,846,988,390,900.00 Juli 19 24,403,585,445.00 24,380,834,065.53 24,324,869,992.18 24,436,798,138.89 130,582,837.82 24,772,615,377.06 -369,029,932.06 136,183,090,757,102,000.00 Agustus 20 24,272,090,440.00 24,304,713,527.66 24,310,760,467.02 24,298,666,588.30 -14,109,525.16 24,567,380,976.71 -295,290,536.71 87,196,501,069,587,200.00 September 21 24,082,631,404.00 24,149,256,041.10 24,197,707,368.87 24,100,804,713.32 -113,053,098.14 24,284,557,063.14 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,430,941,368.03 24,360,971,168.28 24,500,911,567.78 163,263,799.41 23,987,751,615.18 563,912,035.82 317,996,784,142,665,000.00 Oktober 23 24,612,143,420.00 24,557,782,804.41 24,498,739,313.57 24,616,826,295.25 137,768,145.29 24,664,175,367.19 -52,031,947.19 2,707,323,527,907,630.00 Desember 24 20,195,839,321.00 21,504,422,366.02 22,402,717,450.29 20,606,127,281.76 -2,096,021,863.28 24,754,594,440.54 -4,558,755,119.54 20,782,248,239,887,100,000.00 2011 Januari 25 18,547,485,425.00 19,434,566,507.31 20,325,011,790.20 18,544,121,224.41 -2,077,705,660.09 18,510,105,418.47 37,380,006.53 1,397,264,887,857,640.00 Februari 26 22,317,670,660.00 21,452,739,414.19 21,114,421,126.99 21,791,057,701.39 789,409,336.79 16,466,415,564.33 5,851,255,095.67 34,237,186,194,645,600,000.00 Maret 27 23,490,850,795.00 22,879,417,380.76 22,349,918,504.63 23,408,916,256.89 1,235,497,377.63 22,580,467,038.18 910,383,756.82 828,798,584,675,890,000.00 April 28 23,401,919,900.00 23,245,169,144.23 22,976,593,952.35 23,513,744,336.11 626,675,447.72 24,644,413,634.52 -1,242,493,734.52 1,543,790,680,322,770,000.00 Mei 29 24,440,969,550.00 24,082,229,428.27 23,750,538,785.49 24,413,920,071.04 773,944,833.14 24,140,419,783.83 300,549,766.17 90,330,161,947,346,800.00 Juni 30 25,113,931,440.00 24,804,420,836.48 24,488,256,221.18 25,120,585,451.78 737,717,435.69 25,187,864,904.19 -73,933,464.19 5,466,157,126,935,260.00 Juli 31 25,401,258,645.00 25,222,207,302.44 25,002,021,978.07 25,442,392,626.82 513,765,756.88 25,858,302,887.47 -457,044,242.47 208,889,439,573,942,000.00 Agustus 32 25,321,323,110.00 25,291,588,367.73 25,204,718,450.83 25,378,458,284.63 202,696,472.77 25,956,158,383.70 -634,835,273.70 403,015,824,739,276,000.00 September 33 25,080,556,135.00 25,143,865,804.82 25,162,121,598.62 25,125,610,011.02 -42,596,852.21 25,581,154,757.40 -500,598,622.40 250,598,980,749,188,000.00 Oktober 34 25,109,569,925.00 25,119,858,688.95 25,132,537,561.85 25,107,179,816.04 -29,584,036.77 25,083,013,158.81 26,556,766.19 705,261,830,637,409.00 Oktober 35 25,282,275,715.00 25,233,550,607.18 25,203,246,693.58 25,263,854,520.78 70,709,131.73 25,077,595,779.27 204,679,935.73 41,893,876,091,223,800.00 Desember 36 25,569,779,015.00 25,468,910,492.66 25,389,211,352.93 25,548,609,632.38 185,964,659.35 25,334,563,652.52 235,215,362.48 55,326,266,747,430,200.00 SE 442,210,065.06 SSE 59,521,905,067,986,600,000.00 MSE 1,750,644,266,705,490,000.00 Tabel 4.8 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,7 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,8 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,8 21.548.149.420,00 + 1-0,8 21.473.831.050,00 = 21.533.285.746,00 Maret 2009 = 0,8 21.789.329.725,00 + 1-0,8 21.533.285.746,00 = 21.738.120.929,20 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,8 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,8 21.533.285.746,00 + 1-0,8 21.473.831.050,00 = 21.521.394.806,80 Maret 2009 = 0,8 21.738.120.929,20 + 1-0,8 21.521.394.806,80 = 21.694.775.704,72 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.533.285.746,00 – 21.521.394.806,80 = 21.545.176.685,20 Maret 2009 = 221.738.120.929,20 - 21.694.775.704,72 = 21.781.466.153,68 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,8 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = , , 21.533.285.746,00 – 21.521.394.806,80 = 47.563.756,80 Maret 2009 = , , 21.738.120.929,20 - 21.694.775.704,72 = 173.380.897,92 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.545.176.685,20 + 47.563.756,80 1 = 21.592.740.442,00 F April 2009 untuk m = 1 = 21.781.466.153,68 + 173.380.897,92 1 = 21.954.847.051,60 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,533,285,746.00 21,521,394,806.80 21,545,176,685.20 47,563,756.80 Maret 3 21,789,329,725.00 21,738,120,929.20 21,694,775,704.72 21,781,466,153.68 173,380,897.92 21,592,740,442.00 196,589,283.00 38,647,346,190,452,600.00 April 4 22,005,291,800.00 21,951,857,625.84 21,900,441,241.62 22,003,274,010.06 205,665,536.90 21,954,847,051.60 50,444,748.40 2,544,672,641,139,460.00 Mei 5 22,264,141,990.00 22,201,685,117.17 22,141,436,342.06 22,261,933,892.28 240,995,100.44 22,208,939,546.96 55,202,443.04 3,047,309,717,584,970.00 Juni 6 22,481,546,105.00 22,425,573,907.43 22,368,746,394.36 22,482,401,420.51 227,310,052.30 22,502,928,992.72 -21,382,887.72 457,227,887,245,526.00 Juli 7 22,851,209,020.00 22,766,081,997.49 22,686,614,876.86 22,845,549,118.11 317,868,482.50 22,709,711,472.81 141,497,547.19 20,021,555,860,900,300.00 Agustus 8 22,845,663,820.00 22,829,747,455.50 22,801,120,939.77 22,858,373,971.22 114,506,062.91 23,163,417,600.62 -317,753,780.62 100,967,465,095,151,000.00 September 9 22,927,399,070.00 22,907,868,747.10 22,886,519,185.63 22,929,218,308.57 85,398,245.86 22,972,880,034.13 -45,480,964.13 2,068,518,098,524,430.00 Oktober 10 22,854,910,720.00 22,865,502,325.42 22,869,705,697.46 22,861,298,953.38 -16,813,488.17 23,014,616,554.43 -159,705,834.43 25,505,953,550,611,000.00 Oktober 11 22,764,705,655.00 22,784,864,989.08 22,801,833,130.76 22,767,896,847.41 -67,872,566.70 22,844,485,465.21 -79,779,810.21 6,364,818,116,533,580.00 Desember 12 22,819,191,990.00 22,812,326,589.82 22,810,227,898.01 22,814,425,281.63 8,394,767.25 22,700,024,280.71 119,167,709.29 14,200,942,938,540,800.00 2010 Januari 13 22,977,014,134.00 22,944,076,625.16 22,917,306,879.73 22,970,846,370.60 107,078,981.73 22,822,820,048.87 154,194,085.13 23,775,815,887,881,600.00 Februari 14 22,942,268,240.00 22,942,629,917.03 22,937,565,309.57 22,947,694,524.49 20,258,429.84 23,077,925,352.32 -135,657,112.32 18,402,852,123,363,300.00 Maret 15 23,444,261,325.00 23,343,935,043.41 23,262,661,096.64 23,425,208,990.17 325,095,787.07 22,967,952,954.33 476,308,370.67 226,869,663,966,914,000.00 April 16 23,821,534,330.00 23,726,014,472.68 23,633,343,797.47 23,818,685,147.89 370,682,700.83 23,750,304,777.24 71,229,552.76 5,073,649,186,310,590.00 Mei 17 24,200,283,345.00 24,105,429,570.54 24,011,012,415.92 24,199,846,725.15 377,668,618.45 24,189,367,848.72 10,915,496.28 119,148,058,975,542.00 Juni 18 24,451,483,354.00 24,382,272,597.31 24,308,020,561.03 24,456,524,633.58 297,008,145.11 24,577,515,343.60 -126,031,989.60 15,884,062,402,413,900.00 Juli 19 24,403,585,445.00 24,399,322,875.46 24,381,062,412.58 24,417,583,338.35 73,041,851.54 24,753,532,778.69 -349,947,333.69 122,463,136,357,359,000.00 Agustus 20 24,272,090,440.00 24,297,536,927.09 24,314,242,024.19 24,280,831,830.00 -66,820,388.39 24,490,625,189.89 -218,534,749.89 47,757,436,910,515,000.00 September 21 24,082,631,404.00 24,125,612,508.62 24,163,338,411.73 24,087,886,605.50 -150,903,612.46 24,214,011,441.61 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,466,453,422.52 24,405,830,420.37 24,527,076,424.68 242,492,008.63 23,936,982,993.05 614,680,657.95 377,832,311,260,289,000.00 Oktober 23 24,612,143,420.00 24,583,005,420.50 24,547,570,420.48 24,618,440,420.53 141,740,000.11 24,769,568,433.31 -157,425,013.31 24,782,634,817,172,200.00 Desember 24 20,195,839,321.00 21,073,272,540.90 21,768,132,116.82 20,378,412,964.99 -2,779,438,303.66 24,760,180,420.64 -4,564,341,099.64 20,833,209,673,899,500,000.00 2011 Januari 25 18,547,485,425.00 19,052,642,848.18 19,595,740,701.91 18,509,544,994.45 -2,172,391,414.91 17,598,974,661.33 948,510,763.67 899,672,668,807,316,000.00 Februari 26 22,317,670,660.00 21,664,665,097.64 21,250,880,218.49 22,078,449,976.78 1,655,139,516.58 16,337,153,579.54 5,980,517,080.46 35,766,584,549,623,000,000.00 Maret 27 23,490,850,795.00 23,125,613,655.53 22,750,666,968.12 23,500,560,342.93 1,499,786,749.63 23,733,589,493.36 -242,738,698.36 58,922,075,683,781,600.00 April 28 23,401,919,900.00 23,346,658,651.11 23,227,460,314.51 23,465,856,987.70 476,793,346.39 25,000,347,092.56 -1,598,427,192.56 2,554,969,489,928,360,000.00 Mei 29 24,440,969,550.00 24,222,107,370.22 24,023,177,959.08 24,421,036,781.36 795,717,644.57 23,942,650,334.09 498,319,215.91 248,322,040,944,108,000.00 Juni 30 25,113,931,440.00 24,935,566,626.04 24,753,088,892.65 25,118,044,359.44 729,910,933.57 25,216,754,425.93 -102,822,985.93 10,572,566,436,351,800.00 Juli 31 25,401,258,645.00 25,308,120,241.21 25,197,113,971.50 25,419,126,510.92 444,025,078.85 25,847,955,293.01 -446,696,648.01 199,537,895,343,276,000.00 Agustus 32 25,321,323,110.00 25,318,682,536.24 25,294,368,823.29 25,342,996,249.19 97,254,851.80 25,863,151,589.77 -541,828,479.77 293,578,101,486,187,000.00 September 33 25,080,556,135.00 25,128,181,415.25 25,161,418,896.86 25,094,943,933.64 -132,949,926.44 25,440,251,100.99 -359,694,965.99 129,380,468,555,843,000.00 Oktober 34 25,109,569,925.00 25,113,292,223.05 25,122,917,557.81 25,103,666,888.29 -38,501,339.05 24,961,994,007.20 147,575,917.80 21,778,651,513,378,300.00 Oktober 35 25,282,275,715.00 25,248,479,016.61 25,223,366,724.85 25,273,591,308.37 100,449,167.04 25,065,165,549.24 217,110,165.76 47,136,824,075,436,200.00 Desember 36 25,569,779,015.00 25,505,519,015.32 25,449,088,557.23 25,561,949,473.42 225,721,832.38 25,374,040,475.41 195,738,539.59 38,313,575,881,347,200.00 SE 344,835,093.66 SSE 62,182,979,311,960,400,000.00 MSE 1,828,911,156,234,130,000.00 Tabel 4.9 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,8 Universitas Sumatera Utara Universitas Sumatera Utara Tahap pertama dalam perhitungan ini adalah perhitungan Pemulusan Eksponensial Tunggal untuk  = 0,9 dengan menggunakan rumus: ′ = α + 1 − α ′ 4.1 Februari 2009 = 0,921.548.149.420 + 1-0,921.473.831.050,00 = 21.540.717.583,00 Maret 2009 = 0,921.789.329.725 + 1-0,921.540.717.583,00 = 21.764.468.510,80 Dan tahap selanjutnya untuk menghitung peramalan nilai air minum yang disalurkan yaitu mencari Pemulusan Eksponensial Ganda untuk  = 0,9 dengan menggunakan rumus: ′′ = α ′ + 1 − α ′′ 4.2 Februari 2009 = 0,921.540.717.583,00 + 1-0,921.473.831.050,00 = 21.534.028.929,70 Maret 2009 = 0,921.764.468.510,80+1-0,921.534.028.929,70 = 21.741.424.552,69 Selanjutnya dicari nilai a t dengan menggunakan rumus: a t = ′ + ′ − ′′ = 2 ′ − ′′ 4.3 Februari 2009 = 221.481.262.887,00 – 21.474.574.233,70 = 21.487.951.540,30 Maret 2009 = 221.512.069.570,80 - 21.478.323.767,41 = 21.545.815.374,19 Universitas Sumatera Utara Universitas Sumatera Utara Tahap selanjutnya adalah dengan menghitung nilai b t untuk  = 0,9 dengan menggunakan rumus: b t = – ′ − ′′ 4.4 Februari 2009 = 221.540.717.583,00 – 21.534.028.929,70 = 21.547.406.236,30 Maret 2009 = 221.764.468.510,80 – 21.741.424.552,69 = 21.787.512.468,91 Selanjutnya dicari nilai F t+m dengan menggunakan rumus: F t+m = a t + b t m 4.5 F Maret 2009 untuk m = 1 = 21.547.406.236,30 + 60.197.879,70 1 = 21.607.604.116,00 F April 2012 untuk m = 1 = 21.787.512.468,91 + 207.395.622,99 1 = 21.994.908.091,90 Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,540,717,583.00 21,534,028,929.70 21,547,406,236.30 60,197,879.70 Maret 3 21,789,329,725.00 21,764,468,510.80 21,741,424,552.69 21,787,512,468.91 207,395,622.99 21,607,604,116.00 181,725,609.00 33,024,196,966,423,700.00 April 4 22,005,291,800.00 21,981,209,471.08 21,957,230,979.24 22,005,187,962.92 215,806,426.55 21,994,908,091.90 10,383,708.10 107,821,393,906,687.00 Mei 5 22,264,141,990.00 22,235,848,738.11 22,207,986,962.22 22,263,710,513.99 250,755,982.98 22,220,994,389.47 43,147,600.53 1,861,715,431,498,980.00 Juni 6 22,481,546,105.00 22,456,976,368.31 22,432,077,427.70 22,481,875,308.92 224,090,465.48 22,514,466,496.98 -32,920,391.97 1,083,752,207,787,540.00 Juli 7 22,851,209,020.00 22,811,785,754.83 22,773,814,922.12 22,849,756,587.54 341,737,494.42 22,705,965,774.40 145,243,245.60 21,095,600,392,341,700.00 Agustus 8 22,845,663,820.00 22,842,276,013.48 22,835,429,904.35 22,849,122,122.62 61,614,982.23 23,191,494,081.96 -345,830,261.96 119,598,570,087,551,000.00 September 9 22,927,399,070.00 22,918,886,764.35 22,910,541,078.35 22,927,232,450.35 75,111,174.00 22,910,737,104.85 16,661,965.15 277,621,082,724,951.00 Oktober 10 22,854,910,720.00 22,861,308,324.43 22,866,231,599.83 22,856,385,049.04 -44,309,478.52 23,002,343,624.35 -147,432,904.35 21,736,461,285,073,500.00 Oktober 11 22,764,705,655.00 22,774,365,921.94 22,783,552,489.73 22,765,179,354.16 -82,679,110.09 22,812,075,570.52 -47,369,915.52 2,243,908,896,512,570.00 Desember 12 22,819,191,990.00 22,814,709,383.19 22,811,593,693.85 22,817,825,072.54 28,041,204.12 22,682,500,244.06 136,691,745.94 18,684,633,407,909,300.00 2010 Januari 13 22,977,014,134.00 22,960,783,658.92 22,945,864,662.41 22,975,702,655.43 134,270,968.56 22,845,866,276.66 131,147,857.34 17,199,760,485,673,500.00 Februari 14 22,942,268,240.00 22,944,119,781.89 22,944,294,269.94 22,943,945,293.84 -1,570,392.47 23,109,973,623.99 -167,705,383.99 28,125,095,819,505,200.00 Maret 15 23,444,261,325.00 23,394,247,170.69 23,349,251,880.61 23,439,242,460.76 404,957,610.67 22,942,374,901.37 501,886,423.63 251,889,982,222,524,000.00 April 16 23,821,534,330.00 23,778,805,614.07 23,735,850,240.72 23,821,760,987.41 386,598,360.11 23,844,200,071.43 -22,665,741.43 513,735,834,772,572.00 Mei 17 24,200,283,345.00 24,158,135,571.91 24,115,907,038.79 24,200,364,105.03 380,056,798.07 24,208,359,347.52 -8,076,002.52 65,221,816,754,194.20 Juni 18 24,451,483,354.00 24,422,148,575.79 24,391,524,422.09 24,452,772,729.49 275,617,383.30 24,580,420,903.09 -128,937,549.09 16,624,891,565,410,000.00 Juli 19 24,403,585,445.00 24,405,441,758.08 24,404,050,024.48 24,406,833,491.68 12,525,602.39 24,728,390,112.79 -324,804,667.79 105,498,072,219,989,000.00 Agustus 20 24,272,090,440.00 24,285,425,571.81 24,297,288,017.08 24,273,563,126.54 -106,762,007.41 24,419,359,094.07 -147,268,654.07 21,688,056,470,897,100.00 September 21 24,082,631,404.00 24,102,910,820.78 24,122,348,540.41 24,083,473,101.15 -174,939,476.66 24,166,801,119.14 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,506,788,367.98 24,468,344,385.22 24,545,232,350.73 345,995,844.81 23,908,533,624.49 643,130,026.51 413,616,231,003,300,000.00 Oktober 23 24,612,143,420.00 24,601,607,914.80 24,588,281,561.84 24,614,934,267.76 119,937,176.62 24,891,228,195.55 -279,084,775.55 77,888,311,941,508,800.00 Desember 24 20,195,839,321.00 20,636,416,180.38 21,031,602,718.53 20,241,229,642.23 -3,556,678,843.31 24,734,871,444.37 -4,539,032,123.37 20,602,812,617,024,200,000.00 2011 Januari 25 18,547,485,425.00 18,756,378,500.54 18,983,900,922.34 18,528,856,078.74 -2,047,701,796.19 16,684,550,798.92 1,862,934,626.08 3,470,525,421,050,050,000.00 Februari 26 22,317,670,660.00 21,961,541,444.05 21,663,777,391.88 22,259,305,496.23 2,679,876,469.55 16,481,154,282.55 5,836,516,377.45 34,064,923,424,240,700,000.00 Maret 27 23,490,850,795.00 23,337,919,859.91 23,170,505,613.10 23,505,334,106.71 1,506,728,221.22 24,939,181,965.77 -1,448,331,170.77 2,097,663,180,226,410,000.00 April 28 23,401,919,900.00 23,395,519,895.99 23,373,018,467.70 23,418,021,324.28 202,512,854.60 25,012,062,327.93 -1,610,142,427.93 2,592,558,638,215,940,000.00 Mei 29 24,440,969,550.00 24,336,424,584.60 24,240,083,972.91 24,432,765,196.29 867,065,505.21 23,620,534,178.88 820,435,371.12 673,114,198,188,097,000.00 Juni 30 25,113,931,440.00 25,036,180,754.46 24,956,571,076.30 25,115,790,432.62 716,487,103.40 25,299,830,701.50 -185,899,261.50 34,558,535,424,866,800.00 Juli 31 25,401,258,645.00 25,364,750,855.95 25,323,932,877.98 25,405,568,833.91 367,361,801.68 25,832,277,536.01 -431,018,891.01 185,777,284,407,923,000.00 Agustus 32 25,321,323,110.00 25,325,665,884.59 25,325,492,583.93 25,325,839,185.26 1,559,705.95 25,772,930,635.59 -451,607,525.59 203,949,357,166,908,000.00 September 33 25,080,556,135.00 25,105,067,109.96 25,127,109,657.36 25,083,024,562.56 -198,382,926.58 25,327,398,891.21 -246,842,756.21 60,931,346,292,036,400.00 Oktober 34 25,109,569,925.00 25,109,119,643.50 25,110,918,644.88 25,107,320,642.11 -16,191,012.47 24,884,641,635.99 224,928,289.01 50,592,735,198,956,000.00 Oktober 35 25,282,275,715.00 25,264,960,107.85 25,249,555,961.55 25,280,364,254.15 138,637,316.67 25,091,129,629.64 191,146,085.36 36,536,825,950,344,100.00 Desember 36 25,569,779,015.00 25,539,297,124.29 25,510,323,008.01 25,568,271,240.56 260,767,046.46 25,419,001,570.82 150,777,444.18 22,733,837,674,320,500.00 SE 266,869,033.35 SSE 65,253,715,250,307,500,000.00 M SE 1,919,230,000,000,000,000.00 Tabel 4.10 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 a = 0,9 Universitas Sumatera Utara Universitas Sumatera Utara Tabel 4.11 Perbandingan Ukuran Ketepatan Metode Peramalan  MSE 0,1 1.909.785.775.041.190.000,00 0,2 1.791.626.616.500.080.000,00 0,3 1.711.594.945.070.900.000,00 0,4 1.667.313.913.905.640.000,00 0,5 1.661.434.959.739.730.000,00 0,6 1.691.882.551.210.190.000,00 0,7 1.750.644.266.705.490.000,00 0,8 1.828.911.156.234.130.000,00 0,9 1.919.230.000.000.000.000,00 Dari tabel 4.11 di atas dapat dilihat bahwa yang menghasilkan nilai MSE yang paling kecil atau minimum adalah  = 0,5 yaitu dengan MSE = 1.661.434.959.739.730.000,00. Universitas Sumatera Utara Universitas Sumatera Utara Tahun Bulan Periode Nilai Air Minum Xt St St a t b t F t+1 m=1 e i e i 2 2009 Januari 1 21,473,831,050.00 21,473,831,050.00 21,473,831,050.00 Februari 2 21,548,149,420.00 21,510,990,235.00 21,492,410,642.50 21,529,569,827.50 18,579,592.50 Maret 3 21,789,329,725.00 21,650,159,980.00 21,571,285,311.25 21,729,034,648.75 78,874,668.75 21,548,149,420.00 241,180,305.00 58,167,939,519,893,000.00 April 4 22,005,291,800.00 21,827,725,890.00 21,699,505,600.63 21,955,946,179.38 128,220,289.38 21,807,909,317.50 197,382,482.50 38,959,844,397,862,800.00 Mei 5 22,264,141,990.00 22,045,933,940.00 21,872,719,770.31 22,219,148,109.69 173,214,169.69 22,084,166,468.75 179,975,521.25 32,391,188,249,209,200.00 Juni 6 22,481,546,105.00 22,263,740,022.50 22,068,229,896.41 22,459,250,148.59 195,510,126.09 22,392,362,279.38 89,183,825.63 7,953,754,753,110,410.00 Juli 7 22,851,209,020.00 22,557,474,521.25 22,312,852,208.83 22,802,096,833.67 244,622,312.42 22,654,760,274.69 196,448,745.31 38,592,109,534,855,500.00 Agustus 8 22,845,663,820.00 22,701,569,170.63 22,507,210,689.73 22,895,927,651.52 194,358,480.90 23,046,719,146.09 -201,055,326.09 40,423,244,150,664,200.00 September 9 22,927,399,070.00 22,814,484,120.31 22,660,847,405.02 22,968,120,835.61 153,636,715.29 23,090,286,132.42 -162,887,062.42 26,532,195,104,427,800.00 Oktober 10 22,854,910,720.00 22,834,697,420.16 22,747,772,412.59 22,921,622,427.72 86,925,007.57 23,121,757,550.90 -266,846,830.90 71,207,231,160,539,300.00 Oktober 11 22,764,705,655.00 22,799,701,537.58 22,773,736,975.08 22,825,666,100.07 25,964,562.50 23,008,547,435.29 -243,841,780.29 59,458,813,816,444,400.00 Desember 12 22,819,191,990.00 22,809,446,763.79 22,791,591,869.44 22,827,301,658.14 17,854,894.35 22,851,630,662.57 -32,438,672.57 1,052,267,477,997,230.00 2010 Januari 13 22,977,014,134.00 22,893,230,448.89 22,842,411,159.17 22,944,049,738.62 50,819,289.73 22,845,156,552.50 131,857,581.50 17,386,421,800,316,800.00 Februari 14 22,942,268,240.00 22,917,749,344.45 22,880,080,251.81 22,955,418,437.09 37,669,092.64 22,994,869,028.35 -52,600,788.35 2,766,842,935,359,980.00 Maret 15 23,444,261,325.00 23,181,005,334.72 23,030,542,793.27 23,331,467,876.18 150,462,541.46 22,993,087,529.73 451,173,795.27 203,557,793,539,014,000.00 April 16 23,821,534,330.00 23,501,269,832.36 23,265,906,312.81 23,736,633,351.91 235,363,519.55 23,481,930,417.64 339,603,912.36 115,330,817,289,545,000.00 Mei 17 24,200,283,345.00 23,850,776,588.68 23,558,341,450.75 24,143,211,726.61 292,435,137.93 23,971,996,871.46 228,286,473.54 52,114,714,001,932,200.00 Juni 18 24,451,483,354.00 24,151,129,971.34 23,854,735,711.04 24,447,524,231.64 296,394,260.30 24,435,646,864.55 15,836,489.45 250,794,398,149,644.00 Juli 19 24,403,585,445.00 24,277,357,708.17 24,066,046,709.61 24,488,668,706.73 211,310,998.56 24,743,918,491.93 -340,333,046.93 115,826,582,835,218,000.00 Agustus 20 24,272,090,440.00 24,274,724,074.09 24,170,385,391.85 24,379,062,756.32 104,338,682.24 24,699,979,705.30 -427,889,265.30 183,089,223,356,110,000.00 September 21 24,082,631,404.00 24,178,677,739.04 24,174,531,565.44 24,182,823,912.64 4,146,173.60 24,483,401,438.56 -64,916,937.04 4,214,208,714,655,320.00 Oktober 22 24,551,663,651.00 24,365,170,695.02 24,269,851,130.23 24,460,490,259.81 95,319,564.79 24,186,970,086.24 364,693,564.76 133,001,396,178,048,000.00 Oktober 23 24,612,143,420.00 24,488,657,057.51 24,379,254,093.87 24,598,060,021.15 109,402,963.64 24,555,809,824.60 56,333,595.40 3,173,473,970,888,780.00 Desember 24 20,195,839,321.00 22,342,248,189.26 23,360,751,141.56 21,323,745,236.95 -1,018,502,952.31 24,707,462,984.79 -4,511,623,663.79 20,354,748,083,656,200,000.00 2011 Januari 25 18,547,485,425.00 20,444,866,807.13 21,902,808,974.35 18,986,924,639.91 -1,457,942,167.22 20,305,242,284.64 -1,757,756,859.64 3,089,709,177,607,660,000.00 Februari 26 22,317,670,660.00 21,381,268,733.56 21,642,038,853.95 21,120,498,613.17 -260,770,120.39 17,528,982,472.69 4,788,688,187.31 22,931,534,555,265,100,000.00 Maret 27 23,490,850,795.00 22,436,059,764.28 22,039,049,309.12 22,833,070,219.45 397,010,455.16 20,859,728,492.78 2,631,122,302.22 6,922,804,569,228,600,000.00 April 28 23,401,919,900.00 22,918,989,832.14 22,479,019,570.63 23,358,960,093.65 439,970,261.51 23,230,080,674.61 171,839,225.39 29,528,719,382,936,500.00 Mei 29 24,440,969,550.00 23,679,979,691.07 23,079,499,630.85 24,280,459,751.29 600,480,060.22 23,798,930,355.16 642,039,194.84 412,214,327,706,162,000.00 Juni 30 25,113,931,440.00 24,396,955,565.54 23,738,227,598.19 25,055,683,532.88 658,727,967.34 24,880,939,811.51 232,991,628.49 54,285,098,945,802,600.00 Juli 31 25,401,258,645.00 24,899,107,105.27 24,318,667,351.73 25,479,546,858.81 580,439,753.54 25,714,411,500.22 -313,152,855.22 98,064,710,732,701,900.00 Agustus 32 25,321,323,110.00 25,110,215,107.63 24,714,441,229.68 25,505,988,985.59 395,773,877.95 26,059,986,612.34 -738,663,502.34 545,623,769,693,028,000.00 September 33 25,080,556,135.00 25,095,385,621.32 24,904,913,425.50 25,285,857,817.13 190,472,195.82 25,901,762,863.54 -821,206,728.54 674,380,490,995,248,000.00 Oktober 34 25,109,569,925.00 25,102,477,773.16 25,003,695,599.33 25,201,259,946.99 98,782,173.83 25,476,330,012.95 -366,760,087.95 134,512,962,114,441,000.00 November 35 25,282,275,715.00 25,192,376,744.08 25,098,036,171.70 25,286,717,316.45 94,340,572.38 25,300,042,120.82 -17,766,405.82 315,645,175,670,916.00 Desember 36 25,569,779,015.00 25,381,077,879.54 25,239,557,025.62 25,522,598,733.46 141,520,853.92 25,381,057,888.83 188,721,126.17 35,615,663,463,058,100.00 SE 827,618,143.19 SSE 56,488,788,631,150,800,000.00 M SE 1,661,434,959,739,730,000.00 a = 0,5 Tabel 4.12 Peramalan Nilai Air Minum yang Disalurkan PDAM Tirtanadi Medan Tahun 2009 - 2011 Universitas Sumatera Utara Universitas Sumatera Utara Dari Tabel 4.12 diperoleh ukuran ketepatan metode peramalan dengan menggunakan  = 0,5 adalah: 1. SE Sum Eror Jumlah Kesalahan: SE = ∑ SE = 827.618.143,19 2. ME Mean Error Nilai Tengah Kesalahan: ME = ∑ ME = . . , ME = 24341710,09 3. SSE Sum Square Error Jumlah Kuadrat Kesalahan: SSE = ∑ SSE = 56.488.788.631.150.800.000,00 4. MSE Mean Square Error Nilai Tengah Kesalahan Kuadrat: MSE = ∑ MSE = 1.661.434.959.739.730.000,00 5. SDE Standard Deviation of Error Deviasi Standar Kesalahan SDE = ∑ = . . . . . . , = √ 1.711.781.473.671.240.000,00 = 1.308.350.669,00 Universitas Sumatera Utara Universitas Sumatera Utara

4.2 Peramalan Nilai Air Minum