Everitt, as reported in Hand et al. (1994), presented data on the amount of weight gained by 72 anorexic girls under one of three treatment conditions. The conditions were Cognitive Behavior Therapy, Family Therapy, and a Control group who received no treatment. The data follow:

Cog. 1.7 0.7 0.1 0.7 3.5 14.9 3.5 17.1 7.6 1.6 11.7 6.1 1.1 4.0 Behav. 20.9 9.1 2.1 1.4 1.4 0.3 3.7 0.8 2.4 12.6 1.9 3.9 0.1 15.4 0.7 Family 11.4 11.0 5.5 9.4 13.9 2.9 0.1 7.4 21.5 5.3 3.8 13.4 13.1 9.0 3.9 5.7 10.7 Control 0.5 9.3 5.4 12.3 2.0 10.2 12.2 11.6 7.1 6.2 0.2 9.2 8.3 3.3 11.3 0.0 1.0 10.6 4.6 6.7 2.8 0.3 1.8 3.7 15.9 10.2

(a) What would you hypothesize about central tendency and variability?

(b) Calculate the relevant descriptive statistics and graphics for each condition separately.

(c) What kind of conclusions would you feel comfortable in drawing, and why? (We haven’t covered hypothesis testing, but you are doing an elementary hypothesis test here. Think carefully about how you are doing it—it may help you in Chapter 8.)