Students who graduated from college in last year with student loans owed an average of $25,250 (The New York Times, November 2). An economist wants to determine if the average debt has increased since last year. She takes a sample of 40 recent graduates and finds that their average debt was $28,275. Assume that the population standard deviation is $7,250. a. Specify the competing hypotheses to determine whether the average undergraduate debt has increased since last year. b. Calculate the value of the test statistic and the p-value. c. At the 5% significance level, can you conclude that the average undergraduate debt has increased?