Question 14.70

14.70 Writing contrasts.

You’ve been asked to help some administrators analyze survey data on textbook expenditures collected at a large public university. Let , and represent the population mean expenditures on textbooks for the freshmen, sophomores, juniors, and seniors, respectively.

  1. Because juniors and seniors take higher-level courses, which might use more expensive textbooks, the administrators want to compare the average of the freshmen and sophomores with the average of the juniors and seniors. Write a contrast that expresses this comparison.
  2. Write a contrast for comparing the freshmen with the sophomores.
  3. Write a contrast for comparing the juniors with the seniors.