In: Statistics and Probability
A professor takes a random sample of 25 students and administers a test with questions increasing in difficulty. He takes another sample of 25 students and administers a test with questions decreasing in difficulty. He records measures of test anxiety based on a scale from 1 to 10 (most anxious). Using steps below, run an F test to test the claim that the two given samples come from populations with different variances. Use α = 0.01.
Questions with Increasing Difficulty | Questions with Decreasing Difficulty |
3.7 | 4.8 |
4.5 | 6.2 |
2.9 | 5.9 |
1.7 | 5.1 |
4.5 | 7.8 |
6.2 | 9.5 |
3.8 | 6.3 |
2.9 | 8.5 |
1.7 | 8.0 |
4.2 | 6.8 |
4.7 | 6.4 |
3.8 | 4.9 |
3.1 | 5.6 |
3.0 | 8.8 |
1.7 | 9.4 |
2.0 | 9.5 |
1.4 | 6.5 |
2.4 | 7.6 |
1.6 | 6.7 |
5.6 | 8.2 |
6.7 | 5.6 |
5.4 | 4.2 |
3.6 | 7.9 |
2.4 | 8.1 |
3.7 | 6.5 |
A. State the null and alternative hypotheses in terms of σ12 & σ22. Be sure to label which population is which.
B. Find the critical value, Test statistic, and P-value
C. Decision? Reject / Fail to Reject
D. Are the two given samples from populations with different variances? yes/no