Applied Statistics in Business and Economics

5th Edition

ISBN: 9780077837303

Author: David Doane, Lori Seward Senior Instructor of Operations Management

Publisher: McGraw-Hill Education

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Textbook Question

Chapter 10.3, Problem 11SE

In trials of an experimental internet-based method of learning statistics, pretests and post-tests were given to two groups: traditional instruction (22 students) and internet-based (17 students). Pretest scores were not significantly different. On the post-test, the first group (traditional instruction) had a mean score of 8.64 with a standard deviation of 1.88, while the second group (experimental instruction) had a mean score of 8.82 with a standard deviation of 1.70. (a) Construct a 90 percent confidence interval for the true difference of the means assuming equal variances. Show all work clearly. (b) Repeat, using the assumption of unequal variances with cither Welch’s formula for d.f. or the quick rule for degrees of freedom. (c) Did the assumption about variances change the conclusion? (d) Construct separate confidence intervals for each mean. Do they overlap?

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Chapter 10.3, Problem 10SE

Chapter 10.3, Problem 12SE

Chapter 10 Solutions

Applied Statistics in Business and Economics

Ch. 10.2 - Do a two-sample test for equality of means...Ch. 10.2 - Repeat the previous exercise, assuming unequal...Ch. 10.2 - Is there a difference in the average number of...Ch. 10.2 - Prob. 4SE Ch. 10.2 - Prob. 5SE Ch. 10.2 - Prob. 6SE Ch. 10.2 - Prob. 7SE Ch. 10.2 - On a random basis, Bob buys a small take-out...Ch. 10.2 - For a marketing class term project, Bob is...Ch. 10.3 - A special bumper was installed on selected...

Ch. 10.3 - In trials of an experimental internet-based method...Ch. 10.3 - Construct a 95 percent confidence interval for the...Ch. 10.4 - (a) At = .05, does the following sample show that...Ch. 10.4 - An experimental surgical procedure is being...Ch. 10.4 - Blue Box is testing a new half price on Tuesday...Ch. 10.4 - The U.S. governments Cash for Clunkers program...Ch. 10.4 - Prob. 17SE Ch. 10.4 - Below is a random sample of shoe sizes for 12...Ch. 10.4 - A newly installed automatic gate system was being...Ch. 10.5 - Calculate the test statistic and p-value for a...Ch. 10.5 - Prob. 21SE Ch. 10.5 - Prob. 22SE Ch. 10.5 - Prob. 23SE Ch. 10.5 - Prob. 24SE Ch. 10.5 - Prob. 25SE Ch. 10.5 - A survey of 100 mayonnaise purchasers showed that...Ch. 10.5 - Prob. 27SE Ch. 10.5 - Prob. 28SE Ch. 10.5 - When tested for compliance with Sarbanes-Oxley...Ch. 10.5 - In 2009, a sample of 200 in-store shoppers showed...Ch. 10.5 - From a telephone log, an executive finds that 36...Ch. 10.5 - Prob. 32SE Ch. 10.6 - The American Bankers Association reported that, in...Ch. 10.6 - A study showed that 36 of 72 cell phone users with...Ch. 10.6 - Prob. 35SE Ch. 10.7 - Which samples show unequal variances? Use = .10...Ch. 10.7 - Prob. 37SE Ch. 10.7 - Prob. 38SE Ch. 10.7 - A manufacturing process drills holes in sheet...Ch. 10.7 - Examine the data below showing the weights (in...Ch. 10 - (a) Explain why two samples from the same...Ch. 10 - (a) In a two-sample test of proportions, what is a...Ch. 10 - List the three cases for a test comparing two...Ch. 10 - Consider Case 1 (known variances) in the test...Ch. 10 - Consider Case 2 (unknown but equal variances) in...Ch. 10 - Consider Case 3 (unknown and unequal variances) in...Ch. 10 - Why is it a good idea to use a computer program...Ch. 10 - (a) Explain why the paired t test for dependent...Ch. 10 - Explain how a difference in means could be...Ch. 10 - (a) Why do we use an F test? (b) When two...Ch. 10 - (a) In an F test for two variances, explain how to...Ch. 10 - Prob. 41CE Ch. 10 - In an early home game, an NBA team made 66 of...Ch. 10 - Prob. 43CE Ch. 10 - A recent study found that 202 women held board...Ch. 10 - A study of the Fortune 100 board of director...Ch. 10 - Prob. 46CE Ch. 10 - How many full-page advertisements are found in a...Ch. 10 - eShopNet, an online clothing retailer, is testing...Ch. 10 - After John F. Kennedy Jr. was killed in an...Ch. 10 - A ski company in Vail owns two ski shops, one on...Ch. 10 - At a University of Colorado womens home basketball...Ch. 10 - A ski resort tracks the proportion of seasonal...Ch. 10 - Does a follow-up reminder increase the renewal...Ch. 10 - A study revealed that the 30-day readmission rate...Ch. 10 - In a marketing class, 44 student members of...Ch. 10 - In San Francisco, a sample of 3,200 wireless...Ch. 10 - Prob. 57CE Ch. 10 - Prob. 58CE Ch. 10 - Prob. 59CE Ch. 10 - Prob. 60CE Ch. 10 - Prob. 61CE Ch. 10 - Prob. 62CE Ch. 10 - In a 15-day survey of air pollution in two...Ch. 10 - Prob. 64CE Ch. 10 - Do male and female school superintendents earn the...Ch. 10 - The average take-out order size for Ashoka Curry...Ch. 10 - Cash withdrawals from a college credit union for a...Ch. 10 - In Mini Case 10.2, we found that the mean methane...Ch. 10 - A ski company in Vail owns two ski shops, one on...Ch. 10 - A ski company in Vail owns two ski shops, one on...Ch. 10 - Emergency room arrivals in a large hospital showed...Ch. 10 - Concerned about graffiti, mayors of nine suburban...Ch. 10 - A certain company will purchase the house of any...Ch. 10 - Nine homes are chosen at random from real estate...Ch. 10 - Prob. 75CE Ch. 10 - Prob. 76CE Ch. 10 - Prob. 77CE Ch. 10 - Is there a difference between the variance in ages...Ch. 10 - A survey of 100 mayonnaise purchasers showed that...Ch. 10 - A 20-minute consumer survey mailed to 500 adults...Ch. 10 - One group of accounting students used simulation...Ch. 10 - Advertisers fear that users of DVRs (digital video...Ch. 10 - In preliminary tests of a vaccine that may help...Ch. 10 - Prob. 84CE Ch. 10 - Male and female students in a finance class were...Ch. 10 - Prob. 86CE Ch. 10 - A retailer compared the frequency of customer...Ch. 10 - Streeling University surveyed a random sample of...Ch. 10 - The Fischer Theatre compared attendance at its...Ch. 10 - Random samples of tires being replaced by a car...Ch. 10 - Count the number of two-door vehicles among 50...Ch. 10 - Which statement is not correct? Explain. a. The...Ch. 10 - Match each statement to the correct property of an...Ch. 10 - Concerning confidence intervals, which statement...Ch. 10 - Prob. 4ERQ Ch. 10 - Prob. 5ERQ Ch. 10 - Prob. 6ERQ Ch. 10 - Prob. 7ERQ Ch. 10 - Prob. 8ERQ Ch. 10 - The process that produces Sonora Bars (a type of...Ch. 10 - Prob. 10ERQ Ch. 10 - Prob. 11ERQ Ch. 10 - Last month, 85 percent of the visitors to the...Ch. 10 - Weights of 12 randomly chosen Sonora Bars (a type...Ch. 10 - In a random sample of 200 Colorado residents, 150...Ch. 10 - Five students in a large lecture class compared...Ch. 10 - Prob. 16ERQ Ch. 10 - Prob. 17ERQ

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