A consumer advocate wants to find out if motivational speakers can actually improve people's earning power. He randomly selects a group of 25 people in his city and invites them to participate in a motivational course. He pays for the course if the participants all agree to share their income tax figures for the year before and the year after they take the course. He also pays the subjects a fee for participating in the study. The data summarized below is the results in terms of annual income before and after the course. Use a t-test for correlated groups to determine whether or not the motivational speaker has had an effect. What can you conclude if you use the appropriate 1 tail test and an alpha level of 0.01?
| 1 |
35000 |
34887 |
| 2 |
36284 |
36160 |
| 3 |
37438 |
37305 |
| 4 |
37769 |
37684 |
| 5 |
38449 |
38428 |
| 6 |
39755 |
39703 |
| 7 |
41353 |
41245 |
| 8 |
41541 |
41422 |
| 9 |
42539 |
42395 |
| 10 |
42625 |
42495 |
| 11 |
42672 |
42567 |
| 12 |
43607 |
43568 |
| 13 |
43841 |
43748 |
| 14 |
44430 |
44420 |
| 15 |
44487 |
44449 |
| 16 |
44513 |
44504 |
| 17 |
44699 |
44560 |
| 18 |
45111 |
45219 |
| 19 |
45507 |
45609 |
| 20 |
45625 |
45638 |
| 21 |
41257 |
41245 |
| 22 |
41545 |
41422 |
| 23 |
42519 |
42395 |
| 24 |
42625 |
42495 |
| 25 |
42672 |
42567 |