The employee benefits manager of a large public university wants to determine whether differences exist in the proportions of various groups of full-time employees who prefer adopting the second (i.e., plan B) of three available health care plans in the coming annual enrollment period. A random sample of the university’s employees and their tentative health care preferences is given in the file P08_17.xlsx.
a. Perform tests for differences in the proportions of employees within respective classifications who favor plan B in the coming year. For instance, the first such test should examine the difference between the proportion of administrative employees who favor plan B and the proportion of the support staff who prefer plan B.
b. Report a p-value for each of your hypothesis tests and interpret your results. How might the benefits manager use the information you have derived from these tests?