How do private universities and public colleges compare with respect to debt at graduation incurred by students? The file CollegeDebt contains the average debt at graduation incurred by students for 100 private universities and 100 public colleges, as reported by Kiplinger. (Data extracted from "Kiplinger's Best College Values," bit.ly/1QT3L7l.)

a. At the 0.05 level of significance, is there a difference in the variance of average graduation debt incurred by students for private universities and public colleges?

b. Using the results of (a), which t test is appropriate for comparing mean debt at graduation incurred by students at private universities and public colleges?

c. At the 0.05 level of significance, conduct the test selected in (b).

d. Write a short summary of your findings.