7. ADVANCED TOPIC: Patients with two kinds of diagnoses were randomly assigned to one of three types of therapy and the effectiveness of the therapy was measured on a 1-to-15 scale (with a higher number indicating greater effectiveness). There were two patients per cell. Based on the following results,

(a) carry out the analysis of variance (use the .05 significance level),

(b) make a table of cell and marginal means,

(c) make a bar graph of the results, and

(d) describe the results in words (indicate which effects are significant and, on the basis of the significant effects, how to understand the pattern of cell means).