MS 150 Statistics Fall 2001 Quiz 12

 Pretest Posttest 9 13 8 9 8 9 10 11 10 11 6 11 10 10

Use Excel to run a paired t-test on the above data at a significance level of a = 0.05 and a hypothesized mean difference of zero. Use the results for a two-tailed test. Hint: the variance is the square of the standard deviation.

1. What is H0? ___________
2. What is H1? ___________
3. What is a?___________
4. How many tails?___________
5. Report n___________
6. Report x for the pretest___________
7. What is sx for the pretest?___________
8. Report x for the posttest___________
9. What is sx for the posttest?___________
10. Report the correlation coefficient r _________
11. Report the degrees of freedom ___________
12. Report the t-statistic _______
13. Report tc for a two-tailed distribution ___________
14. Make a sketch on the back of the t-distribution including µ, ± tc, the t-statistic, and the area in the tails.
15. Do we reject H0 or do we fail to reject H0?___________
16. Is the difference in the test averages at a = 0.05 statistically significant? _____