Chapter 10, Problem 10.22AC

You may need to use the appropriate appendix table or technology to answer this question. In a study entitled How Undergraduate Students Use Credit Cards, it was reported that undergraduate students have a mean credit card balance of $3,173. This figure was an all-time high and had increased 44% over the previous five years. Assume that a current study is being conducted to determine if it can be concluded that the mean credit card balance for undergraduate students has continued to increase compared to the original report. Based on previous studies, use a population standard deviation  ? = $1,000. (a) State the null and alternative hypotheses. H0: ? < 3,173 Ha: ? ≥ 3,173 H0: ? = 3,173 Ha: ? ≠ 3,173      H0: ? > 3,173 Ha: ? ≤ 3,173 H0: ? ≥ 3,173 Ha: ? < 3,173 H0: ? ≤ 3,173 Ha: ? > 3,173 (b) What is the test statistic for a sample of 170 undergraduate students with a sample mean credit card balance of $3,305? (Round your answer to two decimal places.)   What is…

The Management Department recently purchased a smallcopier for faculty use. Although the workload of the office staff has improved somewhat, the secretaries are still mak-ing too many trips to the Dean’s office when the depart-mental copier is out of service. Sylvia, the departmental secretary, has been keeping track of failure rates and ser-vice times. With a mean time between failures of 100 hours and a mean time to repair of 24 hours, how much of thetime is the new copier available for faculty use?

Periodically, Merrill Lynch customers are asked to evaluate Merrill Lynch financial consultants and services (2000 Merrill Lynch Client Satisfaction Survey). Higher ratings on the client satisfaction survey indicate better service with 7 the maximum service rating. Independent samples of service ratings for two financial consultants are summarized here. Consultant A has 10 years of experience, whereas consultant B has 1 year of experience. Use  = .05 and test to see whether the consultant with more experience has the higher population mean service rating. Consultant A   Consultant B   = 16     = 10   = 6.82     = 6.25   = 0.58     = 0.7   State the null and alternative hypotheses.H0: 1 - 2 Selectgreater than 0greater than or equal to 0less than 0less than or equal to 0equal to 0not equal to 0Item 1Ha: 1 - 2 Selectgreater than 0greater than or equal to 0less than 0less than or equal to 0equal to 0not equal to 0Item 2 Compute the value of the test statistic (to 2 decimals).…