Sallie Mae researchers report that the average college junior has a credit card debt of $2912. Under the assumption that this finding was based on the sample data in file XR09040, construct and interpret the 99% confidence interval for the population mean credit card debt for college juniors. Based on this confidence inter- val, would it seem very unusual if another sample of this size were to result in a mean of $3150? Source: Sandra Block, "Credit Card Reform Swipes Easy Plastic from College Students," USA Today, May 26, 2009, p. 3B.