A dean of a business school claims that the Graduate Management Admission Test (GMAT) scores of applicants to the school’s MBA program have increased during the past 5 years. Five years ago, the mean and standard deviation of GMAT scores of MBA applicants were 560 and 50, respectively. Twenty one applications for this year’s program were randomly selected and the following GMAT scores were recorded. If we assume that the distribution of GMAT scores of this year’s applicants is the same as that of 5 years ago, can we conclude at the 5% significance level that the dean’s claim is true?

570  597  504  603  494  560  549

535  539  637  540  625  500  545

569  577  606  584  607  606  585