a. e Jay L. Devore Probability and Statistics

19. a.

K x 2 ⫹ y 2 10Kx 2 ⫹ .05; Kx 2 ⫹ y 2 10Ky 2 ⫹ .05 b. .556, .549 c. 25.37, 2.87

21. a.

f x 1 , x 2 , x 3 f x 1 , x 2 b. f x 1 , x 2 , x 3 f x 1 23. .15 25. L 2 27. .25 hr

29. 31. a. ⫺

.1082

b. ⫺

.0131

37. a.

25 32.5 40 45 52.5 65 p .04 .20 .25 .12 .30 .09

b. s

2 112.5 312.5 800 p s 2 .38 .20 .30 .12 39. Proportion .1 .2 .3 .4 .5 Probability .000 .000 .000 .001 .005 .027 Proportion .6 .7 .8 .9 1.0 Probability .088 .201 .302 .269 .107

41. a.

1 1.5 2 2.5 3 3.5 4 p .16 .24 .25 .20 .10 .04 .01 b. .85

c. r

1 2 3 p r .30 .40 .22 .08

47. a.

.6826 b. .1056

49. a.

.6026 b. .2981 51. .7720

53. a.

.0062

b. 55. a.

.9838 b. .8926 x x x x 2 2 3 X 1 X 1 , X 2 57. .9616

59. a.

.9986, .9986 b. .9015, .3970 c. .8357 d. .9525, .0003

61. a.

3.5, 2.27, 1.51 b. 15.4, 75.94, 8.71

63. a.

.695 b. 4.0675 . 2.6775

65. a.

.9232 b. .9660 67. .1588

69. a.

2400 b. 1205; independence c. 2400, 41.77

71. a.

158, 430.25 b. .9788

73. a.

Approximately normal with mean 105, SD 1.2649; Approximately normal with mean 100, SD 1.0142 b. Approximately normal with mean 5, SD 1.6213 c. .0068 d. .0010, yes

75. a.

.2, .5, .3 for x 12, 15, 20; .10, .35, .55 for y 12, 15, 20 b. .25 c. No d. 33.35 e. 3.85

77. a.

381,250

b. f

X x k250x ⫺ 10x 2 for 0 x 20 and for 20 , x 30; f Y y results from substituting y for x in f X x. They are not independent. c. .355 d. 25.969 e. 204.6154, ⫺.894 f. 7.66 79. 1

81. a.

400 min b. 70 83. 97 85. .9973

89. b

, c. Chi-squared with n n.

91. a. b.

.9999 93. 26, 1.64

95. a.

.6

b. U 5 rX 1 2

1 2 r 2 Y s W 2 s W 2 1 s E 2 5 k 450x 2 30x 2 1 1 2 x 3 , E m 44.5 X , ES 2 212.25 s 2 Chapter 6

1. a.

8.14, b. .77, c. 1.66, S d. .148 e. .204, S

3. a.

1.348, b. 1.348, c. 1.781, ⫹ 1.28S d. .6736 e. .0846 5. N 1,703,000; T ⫺ N 1,591,300; T ⭈ 1,601,438.281

7. a.

120.6 b. 1,206,000 c. .80 d. 120.0

9. a.

2.11 b. .119

11. b. c.

Use i x i n i and i 1 ⫺ i in place of p i and q i in part b for i 1, 2.

d. ⫺

.245 e. .041

15. a. b.

74.505 uˆ 5 gX i 2 2n pˆ qˆ pˆ c p 1 q 1 n 1 1 p 2 q 2 n 2 d 12 y x d x X X X X X | X

17. b.

.444

19. a. b.

21. b. 23.

, estimate of m 1 ⫺ m 2 is ⫺ .

25. a.

384.4, 18.86 b. 415.42

29. a. b.

.64, .202 33. With x i time between birth i ⫺ 1 and birth i, . 35. 29.5 37. 1.0132 l ˆ 5 6 a 6 i5 1 ix i 5 .0436 uˆ 5 min X i , lˆ 5 n g[X i 2 min X i ] y x m ˆ 1 5 x , mˆ 2 5 y a ˆ 5 5, bˆ 5 28.0⌫1.2 pˆ 5 100lˆ 2 970 pˆ 5 2lˆ 2 .30 5 .20 Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook andor eChapters. Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.