The American College Testing Corporation has a test called the ACT that is used for admissions to college. The American College Testing Corporation reports that students who attend 2-year colleges in the Midwest United States have an average ACT score of 21.5, with a standard deviation of 3.17. The president of the Minneapolis Community College wonders if students who attend her college have a ACT scores that are significantly different from the ACT scores reported by the American College Teaching Corporation. The president would perform a test, and use a z-critical value of .