Chapter 15, Problem 6P

Suppose that the researcher from the previous problem repealed the study of named couples’ initials using twice as many participants and obtaining observed frequencies that exactly double the original values.

The resulting data are as follows:

Same Initial	Different Initials
18	362	400

1. a. Use a chi-square test to determine whether the number of couples with the same last initial is significantly different than would be expected if couples were Hatched randomly. Test with α = .05.
2. b. You should find that the data lead lo rejecting the null hypothesis. However, in problem 5 the decision was fail to reject. How do you explain the fact that the two samples have the same proportions but lead to different conclusions?