15.3 Employees of a certain state university system can choose from among four different health plans. Each plan differs somewhat from the others in terms of hospitalization coverage. Four samples of recently hospitalized individuals were selected, each sample consisting of people covered by a different health plan. The length of the hospital stay (number of days) was determined for each individual selected.

a. What hypotheses would you test to decide whether mean length of stay was related to health plan?

(Note: Carefully define the population characteristics of interest.)

b. If each sample consisted of eight individuals and the value of the ANOVA F statistic was F  4.37, what conclusion would be appropriate for a test with a  .01?

c. Answer the question posed in Part

(b) if the F value given there resulted from sample sizes n1  9, n2  8, n3  7, and n4  8.