# Homework Help

NO EXCEL FILE. SHOW YOUR WORK/STEPSQuestion 3 In a study conducted by American Express, 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 \$11.35 per night.Suppose a follow-up study was done in which a random sample of 30 corporate hotel bookings was analyzed. Only those cases where an error occurred were included in the study.The following 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.

Compute a 95% confidence interval estimate for the mean error in hotel charges. Interpret the confidence interval estimate.
Based on the interval computed in apart a, do these sample data tend to support the results of the America Express study? Explain.

Question 4 The director of state agency believes that the average starting salary for clerical employees in the state is less than \$30,000 per year. To test her hypothesis, she has collected a simple random sample of 100 starting clerical salaries from across the state and found that the sample mean is \$29,750.
State the appropriate null and alternative hypotheses.
Assuming the population standard deviation is known to be \$2,500 and the significance level for the test is to be 0.05, what is the critical value
Referring to your answer in part b, what conclusion should be reached with respect to the null hypothesis?
Referring to your answer in part c, which of the two statistical errors might have been made in this case? Explain.