16.24 Food safety at fairs and in restaurants.

CASE 16.2 The data file used in Example 16.5 (page 16-11) and Exercise 16.23 contains 303 rows, one for each of the 303 respondents. Each row contains the responses of one person to several questions. We wonder if people are more concerned about the safety of food served at fairs than they are about the safety of food served at restaurants. Explain carefully why we cannot answer this question by applying the Wilcoxon rank sum test to the variables “sfair” and “srest.”