20.Atherapist evaluates a sample in a new treatment program after 1 month, after 2 months, and again after 3 months. Such data do not have homogeneous vari¬ ance.

(a) What statistical procedure should be used to analyze the data? Why?

(b) What is the first thing the therapist must do to the data?

(c) If the results are significant, what should the therapist then do?

(d) Ultimately, what will the thera¬ pist be able to identify?