An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. Seven customers were randomly selected and completed both surveys. The results follow.
| Customer |
Pre-training survey |
Post-training survey |
| A |
16 |
18 |
| B |
15 |
15 |
| C |
20 |
20 |
| D |
17 |
20 |
| E |
16 |
18 |
| F |
15 |
16 |
| G |
12 |
18 |
For a 0.10 significance level, what is the critical value?