The Minneapolis Star Tribune newspaper has decided to write an article about gasoline prices in the Twin Cities area (Minneapolis and St. Paul). The Star Tribune has designed a survey and taken a simple random sample of regular unleaded gas prices at 70 area stations. The results are in the Area Gas Prices %u2013 Random Sample file. The Star Tribune's policy is that no data will be reported unless they are 95 percent confident that the numbers are correct. As the new manager of the data verification unit at the Star Tribune, you need to develop a 95 percent confidence interval for the average price of regular unleaded gasoline in the area.
Practical Application Scenario 2
To complete this scenario, use the Sample Size Estimator file provided in the Resources.
The third shift at Microsoft's Windows' security unit in Redmond, Washington is considering replacing its coffee brewing units with new German-made brewers. As the newest member of this elite Microsoft team, you have been assigned to investigate this proposal. Develop a 99 percent confidence interval for the average yield (cups per pound) for the new German coffee brewer. The margin of error should be no bigger than .3 (three-tenths of a cup). Based on experience with the current coffee makers, your best guess for the population standard deviation, sigma, is 1.2 cups. How big of a sample do you need?
Calculate the estimated sample size needed for the above scenario and communicate your findings to the business manager.
Assignment Submission
Use your custom textbook and the resources provided in the studies to help you complete this assignment. If you need additional clarification on any of the topics addressed in this assignment, Youtube.com can be a very valuable resource.
Complete the two practical application scenario answers in one Word file (please submit a .doc rather than a .docx file) and copy the Excel output into that document. Highlight your numerical answers for both practical applications scenarios in yellow, and then right after that numerical solution, be sure to summarize your findings in a three- to five-sentence paragraph to the scenario manager. Submit the assignment for grading and instructor feedback. Review the scoring guide prior to submission to ensure you meet all evaluation criteria.