Can you become addicted to exercise? In a study conducted at the University of Wisconsin at Madison, a random sample of dedicated exercisers who usually work out every day was drawn. Each completed a questionnaire that gauged their mood on a 5-point scale (where 5 = Very relaxed and happy, 4 = Somewhat relaxed and happy, 3 = Neutral feeling, 2 = Tense and anxious, and 1 = Very tense and anxious). The group was then instructed to abstain from all workouts for the next 3 days. Moreover, they were told to be as physically inactive as possible. Each day their mood was measured using the same questionnaire. Column 1 stores the code identifying the respondent and columns 2 through 5 store the measures of mood for the day before the experiment began and for the 3 days of the experiment, respectively.

a. Can we infer that for each day the exercisers abstained from physical activity they were less happy than when they were exercising?

b. Do the data indicate that by the third day moods were improving?

c. Draw two possible conclusions from your findings.