An investigation of the effectiveness of a training program
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.
For a 0.16 significance level, what is the critical value?
| Customer | Pre-training survey | Post-training survey |
| A | 22 | 24 |
| B | 21 | 21 |
| C | 26 | 26 |
| D | 23 | 26 |
| E | 22 | 24 |
| F | 21 | 22 |
| G | 18 | 24 |
Solution
This is testing of hypothesis between two pairs before training and after training.
WE set up null and alternate hypothesis as follows:
H0: mu1 = mu2
Ha: mu1 not equals mu2
Two sided test.
Let us find mean and variance for the two pairs
Observed difference (Sample 1 - Sample 2): -2
Standard Deviation of Difference : 1.1518
df =12
T-Value -1.7364
For 0.16 level, critical value is not available.
| N | Mean | StDev | SE Mean | |
| Sample 1 | 7 | 21.857 | 2.4103 | 0.911 |
| Sample 2 | 7 | 23.857 | 1.8645 | 0.705 |
