A particular paperback book is published in a choice of four different covers. A certain bookstore keeps copies of each cover on its racks. To test the hypothesis that sales are equally divided among the four choices, a random sample of 100 purchases is identified.
a. If the resulting X2 value were 6.4, what conclusion would you reach when using a test with significance level .05?
b. What conclusion would be appropriate at significance level .01 if X2 = 15.3?
c. If there were six different covers rather than just four, what would you conclude if X2 = 13.7 and a test with a = .05 was used?