Use the Analysis of Variance applet for Exercises 55 and 56.

Question 12.55

55. Move the group means so that they are about the same by clicking and dragging the black dots so that they are about even horizontally.

  1. What happens to the value of ?
  2. Explain why this happens, using the concept of between-sample variability and the statistics SSTR, MSTR, and

12.1.55

(a) Decreases (b) Since all of the sample means are changed until they are about the same, SSTR and MSTR should decrease to small numbers. Since the variability of each sample stays the same, MSE stays the same. Thus decreases.