A Study Is Conducted to Determine Whether Sunshine Affects Depression

Multiple Choice

A study is conducted to determine whether sunshine affects depression. Eight individuals are given a questionnaire measuring depression immediately following a run of 10 consecutive days when the sun shone for over 80% of the daylight hours. The same individuals have their depression measured immediately following 10 consecutive days without any sunshine. The following data are collected. The higher the score the greater the depression. Using the Wilcoxon signed ranks test to evaluate the data with a = 0.05 2 tail , what do you conclude? Assume for the purpose of this question, that sunshine was the only systematic difference between the conditions.

A) reject H 0 ; sunshine appears to affect depression
B) reject H 0 ; sunshine has no effect on depression
C) retain H 0 ; we cannot conclude that sunshine affects depression
D) accept H 0 ; sunshine affects depression