A paired t test was used to analyze the results of an experiment where each of 5 students took a test in two environments: one n
oisy and one quiet. Which of the following distributions must be approximately Normal for the conditions to be satisfied? I. The distribution of test scores in a noisy environment
II. The distribution of test scores in a quiet environment
III. The distribution of differences in test scores
(a) I only
(b) II only
(c) III only
