In a study conducted by a credit card company, corporate clients were surveyed to determine the extent to which hotel room rates quoted by central reservation systems differ from the rates negotiated by the companies. The study found that the mean overcharge by hotels was $11.51 per night. Suppose a follow-up study was done in which a random sample of 30 corporate hotel bookings was analyzed. Only those cases in which an error occurred were included in the study. The accompanying data show the amounts by which the quoted rate differs from the negotiated rate. Positive values indicate an overcharge and negative values indicate an undercharge. Complete parts a and b below. @ Click the icon to view the charge difference data. a. Compute a 95% condence interval estimate for the mean error in hotel charges. lnterpretthe confidence interval estimate. The 95% condence interval is $ $ . (Round to the nearest cent as needed. Use ascending order.) Charge Differences