A therapist would like to evaluate the effectiveness of a procedure for treating depression. A sample of n = 9 depressed clients is obtained and each person's level of depression is measured using a...

A therapist would like to evaluate the effectiveness of a procedure for treating depression. A sample of
n
= 9 depressed clients is obtained and each person's level of depression is measured using a standardized questionnaire before they begin the therapy program. Two weeks after therapy, each client's level of depression is measured again. For this sample, the average level of depression dropped by
MD = 4.7 points following therapy. The difference scores had a variance of
s2 = 36. Do these data indicate a significant change in depression? Use a two-tailed test with a = .01. I