Modern Business Statistics with Microsoft Excel (MindTap Course List)
5th Edition
ISBN: 9781285433301
Author: David R. Anderson, Dennis J. Sweeney, Thomas A. Williams
Publisher: Cengage Learning
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Chapter 12.3, Problem 22E
Error Rates in Tax Preparation. A tax preparation firm is interested in comparing the quality of work at two of its regional offices. The observed frequencies showing the number of sampled returns with errors and the number of sampled returns that were correct are as follows.
- a. What are the sample proportions of returns with errors at the two offices?
- b. Use the chi-square test procedure to see if there is a significant difference between the population proportion of error rates for the two offices. Test the null hypothesis H0: p1 = p2 with a .10 level of significance. What is the p-value and what is your conclusion? Note: We generally use the chi-square test of equal proportions when there are three or more populations, but this example shows that the same chi-square test can be used for testing equal proportions with two populations.
- c. In the Section 10.2, a z test was used to conduct the above test. Either a χ2 test statistic or a z test statistic may be used to test the hypothesis. However, when we want to make inferences about the proportions for two populations, we generally prefer the z test statistic procedure. Refer to the Notes and Comments at the end of this section and comment on why the z test statistic provides the user with more options for inferences about the proportions of two populations.
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Chapter 12 Solutions
Modern Business Statistics with Microsoft Excel (MindTap Course List)
Ch. 12.1 - Test the following hypotheses by using the χ2...Ch. 12.1 - Suppose we have a multinomial population with four...Ch. 12.1 - Television Audiences Across Networks. During the...Ch. 12.1 - M&M Candy Colors. Mars, Inc. manufactures M&M’s,...Ch. 12.1 - Prob. 5ECh. 12.1 - Traffic Accidents by Day of Week. The National...Ch. 12.2 - The following table contains observed frequencies...Ch. 12.2 - Prob. 8ECh. 12.2 - Airline Ticket Purchases for Domestic and...Ch. 12.2 - Hiring and Firing Plans at Private and Public...
Ch. 12.2 - Health insurance benefits vary by the size of the...Ch. 12.2 - Vehicle Quality Ratings. A J. D. Power and...Ch. 12.2 - Company Reputation and Management Quality Survey....Ch. 12.2 - Prob. 14ECh. 12.2 - Prob. 15ECh. 12.2 - Prob. 16ECh. 12.3 - Use the sample data below to test the...Ch. 12.3 - 2. reconsider the observed frequencies in exercise...Ch. 12.3 - Late Flight Comparison Across Airlines. The sample...Ch. 12.3 - Electronic Component Supplier Quality Comparison....Ch. 12.3 - Kate Sanders, a researcher in the department of...Ch. 12.3 - Error Rates in Tax Preparation. A tax preparation...Ch. 12.3 - Social networking is becoming more and more...Ch. 12.3 - Supplier Quality: Three Inspection Outcomes. The...Ch. 12 - In 2011, the industries with the most complaints...Ch. 12 - Bistro 65 is a chain of Italian restaurants with...Ch. 12 - Based on sales over a six-month period, the five...Ch. 12 - Pace-of-Life Preference By Gender. A Pew Research...Ch. 12 - Church Attendance by Age Group. The Barna Group...Ch. 12 - Ambulance Calls by Day of Week. An ambulance...Ch. 12 - Prob. 31SECh. 12 - Phoenix Marketing International identified...Ch. 12 - Prob. 33SECh. 12 - In a study conducted by Zogby International for...
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