the director of admissions of a distinguished mba program is interested in studying the proportion of entering students in similar graduate business programs who have achieved a composite score on the graduate management admissions test (gmat) in excess of 630. specifically, the admissions director believes that the proportion of students entering top rated graduate programs with such composite gmat scores is higher in 2016 than it was in 2012. to test this hypothesis, he has collected random samples of mba candidates entering his program in the fall of 2016 and in the fall of 2012. he believes that these gmat scores are indicative of the scores earned by their peers in his program and in competitors programs. the gmat scores for the random students entering in each year are provided on the left