Grand Bus352 week 6 homework

Complete Problems 9.3, 9.13, 9.14, 9.25, 9.48, and 9.55 in the textbook.

Submit one Excel file. Put each problem result on a separate sheet in your file.

You are required to show all of your work/formulas to receive credit for the assignments.

9.3If you use a 0.10 level of significance in a two-tail hypothesis test, what is your decision rule for rejecting a null hypothesis that the population mean equals 500 if you use theZtest?

9.13Do business seniors at your school prepare for class more than, less than, or about the same as business seniors at other schools? The National Survey of Student Engagement (NSSE)found that business seniors spent a mean of 14 hours per week preparing for class. (Source: A Fresh Look at Student EngagementAnnual Results 2013,available atbit.ly/1j3Ob7N.)

A.State the null and alternative hypotheses to try to prove that the mean number of hours preparing for class by business seniors at your school is different from the 14-hour-per-week benchmark reported by the NSSE.

B.What is a Type I error for your test?

C.What is a Type II error for your test?

9.14The quality-control manager at a compact fluorescent light bulb (CFL) factory needs to determine whether the mean life of a large shipment of CFLs is equal to 7,500 hours. The population standard deviation is 1,000 hours. A random sample of 64 CFLs indicates a sample mean life of 7,250 hours.

A.At the 0.05 level of significance, is there evidence that the mean life is different from 7,500 hours?

B.Compute thep-value and interpret its meaning.

C.Construct a 95% confidence interval estimate of the population mean life of the CFLs.

D.Compare the results of (a) and (c). What conclusions do you reach?

9.25A manufacturer of chocolate candies uses machines to package candies as they move along a filling line. Although the packages are labeled as 8 ounces, the company wants the packages to contain a mean of 8.17 ounces so that virtually none of the packages contain less than 8 ounces. A sample of 50 packages is selected periodically, and the packaging process is stopped if there is evidence that the mean amount packaged is different from 8.17 ounces. Suppose that in a particular sample of 50 packages, the mean amount dispensed is 8.159 ounces, with a sample standard deviation of 0.051 ounce.

A.Is there evidence that the population mean amount is different from 8.17 ounces? (Use a 0.05 level of significance.)

B.Determine thep-value and interpret its meaning.

9.48A quality improvement project was conducted with the objective of improving the wait time in a county health department (CHD) Adult Primary Care Unit (APCU). The evaluation plan includedwaiting room timeas one key waiting time process measure. Waiting room time was defined as the time elapsed between requesting that the patient be seated in the waiting room and the time he or she was called to be placed in an exam room. Suppose that, initially, a targeted wait time goal of 25 minutes was set. After implementing an improvement framework and process, the quality improvement team collected data on a sample of 355 patients. In this sample, the mean wait time was23.05 minutes, with a standard deviation of 16.83 minutes. (Data extracted from M. Michael, S. D. Schaffer, P. L. Egan, B. B. Little, and P. S. Pritchard, “Improving Wait Times and Patient Satisfaction in Primary Care,”Journal for Healthcare Quality, 2013, 35(2), pp. 50-60.)

A.If you test the null hypothesis at the 0.01 level of significance, is there evidence that the population mean wait time is less than 25 minutes?

B.Interpret the meaning of thep-value in this problem

9.55According to a recent National Association of Colleges and Employers (NACE) report, 48% of college student internships are unpaid. (Source: “Just 38 Percent of Unpaid Internships Were Subject to FLSA Guidelines,”bit.ly/Rx76M8.) A recent survey of 60 college interns at a local university found that 30 had unpaid internships.

A.Use the five-stepp-value approach to hypothesis testing and a 0.05 level of significance to determine whether the proportion of college interns that had unpaid internships is different from 0.48.

B.Assume that the study found that 37 of the 60 college interns had unpaid internships and repeat (a). Are the conclusions the same?