Question

PAIRED SAMPLES T TEST A Corporation Psychologist believes that exercise affects self-image. To investigate this probability, 14 employees of the corporation are randomly selected to participate in a jogging program. Before beginning the program, they are given a questionnaire that measures self-image. Then they begin the jogging program. They jogged 4 days a week for 20 minutes. Each employee’s self-image is measured again after two months on the program. The results are as follows: the higher the score, the higher the self-image.

Subject       Before Jogging Self-Image       After Jogging Self-Image

1               14                   20
2               13                   16
3               8                   15
4               14                   12
5               12                   15
6               7                   13
7               10                   12
8               16                   13
9               10                   16
10               14                   18
11               6                   14
12               15                   17
13               12                   18
14               9                   15

Please state your null hypothesis and alternative hypothesis, both as an equation and in your own words. After you run the data through SPSS, please write up the results.

Answer 1

The SPSS output is:

The hypothesis being tested is:

H₀: µ_d = 0

H_a: µ_d ≠ 0

The test statistic is -4.402.

The p-value is 0.001.

Since the p-value (0.001) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that exercise affects self-image.