William H. Knapp III

You will not be able to submit your work for credit, because you are not logged in. Log in!

This homework was due on Monday, November 12 at 06:00 a.m. Turkish time. Late submissions receive half credit.

By checking the box below, you certify that the answers you will submit here represent your own work.

1. For the following questions you will need to use this data. In the data contains scores on 4 tests. Please make sure you use the appropriate part of the data for each question. What is the unbiased estimate of the sample variance for test 1?

2. What's the standard error of the mean?

3. You heard that this instructor is inflating grades. You want to test this using a null hypothesis that the mean grade is less than or equal to 75 with an alpha of .01. What is the upper critical value? If there is no upper critical value, enter na.

4. What is the lower critical value? If there is no lower critical value, enter na.

5. What is t-score for the mean score on test 1?

6. What should you do?
Fail to reject the null.
Reject the null.
Not enough information to tell.

7. For test two, what is the 'unbiased' estimate of the standard deviation?

8. What's the mean test 2 score.

9. What's the upper limit for the 95% confidence interval for the mean test 2 score? If there is no upper limit, enter na.

10. What's the lower limit for the 95% confidence interval for the mean test 2 score? If there is no lower limit, enter na.

11. If your null hypothesis was that the mean score for test 2 was 67, what should you do for an alpha level of .05?
Fail to reject the null.
Reject the null.
Not enough information to tell.

12. Imagine you gave test 3 and you want to figure out if you should curve. You decided to curve it if the the mean is significantly below 75. You make your decision using an alpha of .01. What's the p-value associated with your test?

13. What do you do?
Fail to reject the null.
Reject the null.
Not enough information to tell.

14. What's the upper limit of the smallest 99% confidence interval for the mean you observed? If there is no upper limit, enter na.

15. What's the lower limit of the smallest 99% confidence interval for the mean you observed? If there is no lower limit, enter na.

16. An instructor is reviewing test 4 and trying to figure out if they need to make it harder. They decide they'll make it harder if the mean is significantly above the 75 using an alpha of .01. What is the t-value?

17. What's the p-value associated with their test?

18. What should they do?
Fail to reject the null.
Reject the null.
Not enough information to tell.

19. What's the upper limit of the smallest 99% confidence interval for the mean you observed? If there is no upper limit, enter na.

20. What's the lower limit of the smallest 99% confidence interval for the mean you observed? If there is no lower limit, enter na.