9.78 The manufacturer of Boston and Vermont asphalt shingles provides its customers with a 20-year..

9.78 The manufacturer of Boston and Vermont asphalt shingles provides its customers with a 20-year warranty on most of its products. To determine whether a shingle will last through the warranty period, accelerated-life testing is conducted at the manufacturing plant. Accelerated-life testing exposes the shingle to the stresses it would be subject to in a lifetime of normal use in a laboratory setting via an experiment that takes only a few minutes to conduct. In this test, a shingle is repeatedly scraped with a brush for a short period of time, and the shingle granules removed by the brushing are weighed (in grams). Shingles that experience low amounts of granule loss are expected to last longer in Pallet Moisture 358 CHAPTER 9 Fundamentals of Hypothesis Testing: One-Sample Tests MANAGING ASHLAND MULTICOMM SERVICES Continuing its monitoring of the upload speed first described in the Chapter 6 Managing Ashland MultiComm Services case on page 244, the technical operations department wants to ensure that the mean target upload speed for all Internet service subscribers is at least 0.97 on a standard scale in which the target value is 1.0. Each day, upload speed was measured 50 times, with the following results (stored in ). AMS9 Calculate the sample statistics and determine whether there is evidence that the population mean upload speed is less than 0.97. Write a memo to management that summarizes your conclusions. 1.052 0.678 1.162 0.808 1.012 0.859 0.951 1.112 1.003 0.972 1.223 1.024 0.884 0.799 0.870 0.898 0.621 0.818 1.113 1.286 1.012 0.695 0.869 0.734 1.131 0.993 0.762 0.814 1.108 0.805 1.091 1.086 1.141 0.931 0.723 0.934 1.060 1.047 0.800 0.889 0.854 1.023 1.005 1.030 1.219 0.977 1.044 0.778 1.122 1.114 Apply your knowledge about hypothesis testing in this Digital Case, which continues the cereal-fill-packaging dispute first discussed in the Digital Case from Chapter 7. In response to the negative statements made by the Concerned Consumers About Cereal Cheaters (CCACC) in the Chapter 7 Digital Case, Oxford Cereals recently conducted an experiment concerning cereal packaging. The company claims that the results of the experiment refute the CCACC allegations that Oxford Cereals has been cheating consumers by packaging cereals at less than labeled weights. Open OxfordCurrentNews.pdf, a portfolio of current news releases from Oxford Cereals. Review the relevant DIGITAL CASE press releases and supporting documents. Then answer the following questions: 1. Are the results of the experiment valid? Why or why not? If you were conducting the experiment, is there anything you would change? 2. Do the results support the claim that Oxford Cereals is not cheating its customers? 3. Is the claim of the Oxford Cereals CEO that many cereal boxes contain more than 368 grams surprising? Is it true? 4. Could there ever be a circumstance in which the results of the Oxford Cereals experiment and the CCACC’s results are both correct? Explain REFERENCES 1. Bradley, J. V., Distribution-Free Statistical Tests (Upper Saddle River, NJ: Prentice Hall, 1968). 2. Daniel, W., Applied Nonparametric Statistics, 2nd ed. (Boston: Houghton Mifflin, 1990). 3. Microsoft Excel 2010 (Redmond, WA: Microsoft Corp., 2007). 4. Minitab Release 16 (State College, PA: Minitab Inc., 2010). normal use than shingles that experience high amounts of granule loss. The file contains a sample of 170 measurements made on the company’s Boston shingles and 140 measurements made on Vermont shingles. a. For the Boston shingles, is there evidence that the population mean granule loss is different from 0.50 grams? b. Interpret the meaning of the p-value in (a). c. For the Vermont shingles, is there evidence that the population mean granule loss is different from 0.50 grams? Granule d. Interpret the meaning of the p-value in (c). e. In (a) through (d), do you have to worry about the normality assumption? Explain