College admissions administrators at a university are reevaluating their entrance requirements. They believe that the mean GPA for graduating high school seniors has increased dramatically over the last decade. They randomly sample 85 records of graduating seniors from10

10years ago (sample1) and find an average GPA of2.68. An independent random sample of80 current graduating seniors yields an average GPA of2.94. If the population variance of high school GPAs is0.2601, find a95%confidence interval for the difference in population mean GPA over the last decade.