A pet food company has the business objective of expanding its product line beyond its current kidney- and shrimp-based cat foods. The company developed two new products-one based on chicken livers and the other based on salmon. The company conducted an experiment to compare the two new products with its two existing ones, as well as a generic beef-based product sold in a supermarket chain.
For the experiment, a sample of 50 cats from the population at a local animal shelter was selected. Ten cats were randomly assigned to each of the five products being tested. Each of the cats was then presented with 3 ounces of the selected food in a dish at feeding time. The researchers defined the variable to be measured as the number of ounces of food that the cat consumed within a 10-minute time interval that began when the filled dish was presented. The results for this experiment are summarized in the following table and stored in CatFood:

a. At the 0.05 level of significance, is there evidence of a significant difference in the median amount of food eaten among the various products?
b. Compare the results of (a) with those of Problem 11.13 (a) on page 403.
c. Which test is more appropriate for these data: the Kruskal-Wallis rank test or the one-way ANOVA F test? Explain.