22 50 70
20 400
23 45 80
35 1225
24 40 60
20 400
25 35 55
20 400
26 65 60
-5 25
27 45 75
30 900
28 70 75
5 25
29 35 60
25 625
30 55 65
10 100
31 30 45
15 225
32 65 55
-10 100
33 40 55
15 225
34 60 75
15 225
35 70 65
-5 25
36 55 70
15 225
37 40 75
35 1225
38 35 70
35 1225
39 70 70
40 45 70
25 625
N=40 ∑Y
1
=2095 ∑Y
2
=2765 ∑Y=670
∑Y
2
=17850
The table showed the students’ reading scores of reading pre-test and post-test from the control group. From the table, the writer got ∑Y
1
= 2095, ∑Y
2
= 2765, ∑ Y= 670, ∑Y
2
= 17850. This result is to find out the mean gained of each group and the t-test.
B. Data Analysis
After making the table of the reading test score of the experiment group and the control group, the writer would like to analyze the data that is
comparing the mean of gained score of each group.
Based on the alternative hypothesis that is mentioned in the chapter II, the writer used the hypothesis to conduct the data by using t-test. The
process is as follow: Firstly, the writer had to find the mean of gained score from the
experiment group and the control group. From the experiment group, the writer got:
Mx = X
N = 930
40
= 23.25 The next step is to find out the mean gained score of control group:
My = Y
N = 670
40 = 16.75
From the calculation above, the writer got the mean gained score of each group that is 23.25 for the experiment group and 16.75 for the control
group. After the writer got the mean gained score of each group experiment
group and control group, she will find the deviation of each group, the calculation is as follow:
From the experiment group, the writer got: X = ∑X
2
∑X
2
N
= 26100 – 930
2
40 = 21600 – 864900
40 = 26100 – 21622.5
= 4477.5 This score is showed the deviation of the experiment group. The
next step is to find out the deviation of control group. Y = ∑Y
2
– ∑Y
2
N = 17850 – 670
2
40 = 17850 – 448900
40 = 17850 – 11222.5
= 6627.5
After the writer found the deviation of gained score of each group, experiment group 4327.5 and control group 6627.5 she calculated the score
to the formula of t-test, the formula that the writer used is from Arikunto. The formula is as follow:
1
Mx – My t =
∑X
2
+ ∑Y
2
1 + 1 √ Nx + Ny - 2 Nx Ny
1
Suharsimi Arikunto, Prosedur Penelitian,…, p. 312
t = 23.25 – 16.75
4477.5 + 6627.5 1 + 1 √ 40 + 40 – 2
40 40 =
6.5 11105 2
√ 78 40 =
6.5
22210 √
3120 =
6.5 √ 7.1185897
= 6.5
2.67 =
2.434
Based on the calculation above, it is showed that the results of the t-test from the experiment group and the control group is 2.434.
After the writer got the results from the t-test, she should find the degree of freedom. It is used to find out the value of the t-test score in the t-
table. To get the value of the t-test from the t-table, the writer used the value of the significant of 5 . The procedure to get the degree of freedom is as
follow:
2
2
Suharsimi Arikunto, Prosedur Penelitian,…., p. 312
df = Nx + Ny - 2 = 40 + 40 – 2
= 78
After the writer got the results from the analysis data, she interpreted the results into the t-table. The criteria that is used to test the success of the
hypothesis is based on Anas Sudijono: 1. If t
o
t
t
it means that the alternative hypothesis is accepted and the null hypothesis is rejected. On the other hand, there is significant difference
between the mean of the variable. 2. If t
o
t
t
it means that the alternative hypothesis is rejected and the null hypothesis is accepted. On the other hand, there is no significant difference
between the mean of the variable.
3
C. Data Interpretation
