Income of College Students’ Parents

Income of College Students’ Parents A large university reports that the mean salary of parents of an entering class is $91,600. To see how this compares to his university, a president surveys 28 randomly selected families and finds that their average income is $88,500. If the standard deviation is $10,000, can the president conclude that there is a difference? At a = 0.10, is he correct?

Source: Chronicle of Higher Education.