The Survey of Study Habits and Attitudes SSHA is a psycholog

The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitudes, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a Normal distribution with mean mu = 115 and standard deviation sigma = 25. You suspect that incoming freshman have a mean mu, which is different from 115, since they are often excited yet anxious about entering college. To verify your suspicion, you test the hypotheses H0: mu = 115, Ha: mu not equal to 115 You give the SSHA to 25 incoming freshman and find their mean score. Based on this, you reject H0 at significance level sigma = 0.01. Which of the following would be most helpful in assessing the practical significance of your results? A. Test the hypotheses again, this time using significance level sigma = 0.001. B. Report the P-value of your test. C. Take another sample and retest just to make sure the results are not due to chance. D. Construct a 99% confidence interval for mu to see the magnitude of the difference between 115 and your sample results.

Solution

Choose D.