Everitt, in Hand et al., 1994, reported on several different therapies as treatments for anorexia. There were 29 girls in a cognitive-behavior therapy condition, and they were weighed before and after...

Everitt, in Hand et al., 1994, reported on several different therapies as treatments for anorexia. There were 29 girls in a cognitive-behavior therapy condition, and they were weighed before and after treatment. The weight gains of the girls, in pounds, are given below. The scores were obtained by subtracting the Before score from the After score, so that a negative difference represents weight loss, and a positive difference represents a gain.

a. What does the distribution of these values look like? b. Did the girls in this group gain a statistically significant amount of weight?