Statistics for Business & Economics
12th Edition
ISBN: 9781285528830
Author: David R. Anderson
Publisher: Cengage Learning US
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Chapter 10.1, Problem 8E
Will improving customer service result in higher stock prices for the companies providing the better service? “When a company’s satisfaction score has improved over the prior year’s results and is above the national average (currently 75.7), studies show its shares have a good chance of outperforming the broad stock market in the long run” (Businessweek, March 2, 2009). The following satisfaction scores of three companies for the 4th quarters of 2007 and 2008 were obtained from the American Customer Satisfaction Index. Assume that the scores are based on a poll of 60 customers from each company. Because the polling has been done for several years, the standard deviation can be assumed to equal 6 points in each case.
| Company | 2007 Score | 2008 Score |
| Rite Aid | 73 | 76 |
| Expedia | 75 | 77 |
| J.C. Penney | 77 | 78 |
- a. For Rite Aid, is the increase in the satisfaction score from 2007 to 2008 statistically significant? Use α = .05. What can you conclude?
- b. Can you conclude that the 2008 score for Rite Aid is above the national average of 75.7? Use α = .05.
- c. For Expedia, is the increase from 2007 to 2008 statistically significant? Use α = .05.
- d. When conducting a hypothesis test with the values given for the standard deviation,
sample size , and α, how large must the increase from 2007 to 2008 be for it to be statistically significant? - e. Use the result of part (d) to state whether the increase for J.C. Penney from 2007 to 2008 is statistically significant.
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Chapter 10 Solutions
Statistics for Business & Economics
Ch. 10.1 - The following results come from two independent...Ch. 10.1 - Consider the following hypothesis test....Ch. 10.1 - Consider the following hypothesis test....Ch. 10.1 - Cond Nast Traveler conducts an annual survey in...Ch. 10.1 - The USA Today reports that the average expenditure...Ch. 10.1 - Suppose that you are responsible for making...Ch. 10.1 - Consumer Reports uses a survey of readers to...Ch. 10.1 - Will improving customer service result in higher...Ch. 10.2 - The following results are for independent random...Ch. 10.2 - Consider the following hypothesis test....
Ch. 10.2 - Consider the following data for two independent...Ch. 10.2 - The U.S. Department of Transportation provides the...Ch. 10.2 - The average annual cost (including tuition, room,...Ch. 10.2 - Are nursing salaries in Tampa, Florida, lower than...Ch. 10.2 - Commercial real estate prices and rental rates...Ch. 10.2 - The College Board provided comparisons of...Ch. 10.2 - Periodically, Merrill Lynch customers are asked to...Ch. 10.2 - Researchers at Purdue University and Wichita State...Ch. 10.3 - Consider the following hypothesis test. H0:d0Ha:d0...Ch. 10.3 - The following data are from matched samples taken...Ch. 10.3 - A market research firm used a sample of...Ch. 10.3 - The price per share of stock for a sample of 25...Ch. 10.3 - Bank of Americas Consumer Spending Survey...Ch. 10.3 - The Global Business Travel Association reported...Ch. 10.3 - The College Board SAT college entrance exam...Ch. 10.3 - Scores in the first and fourth (final) rounds for...Ch. 10.3 - A manufacturer produces both a deluxe and a...Ch. 10.4 - Consider the following results for independent...Ch. 10.4 - Consider the hypothesis test H0:p1p20Ha:p1p20 The...Ch. 10.4 - A Businessweek/Harris survey asked senior...Ch. 10.4 - The Professional Golf Association (PGA) measured...Ch. 10.4 - An American Automobile Association (AAA) study...Ch. 10.4 - Chicago OHare and Atlanta Hartsfield-Jackson are...Ch. 10.4 - Businessweek reported that there seems to be a...Ch. 10.4 - In a test of the quality of two television...Ch. 10.4 - Winter visitors are extremely important to the...Ch. 10.4 - The Adecco Workplace Insights Survey sampled men...Ch. 10 - Safegate Foods, Inc., is redesigning the checkout...Ch. 10 - Home values tend to increase over time under...Ch. 10 - Mutual funds are classified as load or no-load...Ch. 10 - The National Association of Home Builders provided...Ch. 10 - Prob. 42SECh. 10 - Country Financial, a financial services company,...Ch. 10 - A large automobile insurance company selected...Ch. 10 - Medical tests were conducted to learn about...Ch. 10 - Vacation occupancy rates were expected to be up...Ch. 10 - Prob. 47SECh. 10 - One of the researchers voiced concern about the...
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