Basic Business Statistics, Student Value Edition

14th Edition

ISBN: 9780134685113

Author: Mark L. Berenson, David M. Levine, David F. Stephan, Kathryn Szabat

Publisher: PEARSON

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Textbook Question

Chapter 9, Problem 75PS

Call centers today play an important role in managing day-to-day business communication with customers. Itâ€™s important, therefore, to monitor a comprehensive set of metrics, which can help businesses understand the overall performance of a call center. One key metric for measuring overall call center performance is service level which is defined as the percentage of calls answered by a human agent within a specified number of seconds. The file ServiceLevel contains the following data for time, in seconds, to answer 50 incoming calls to financial service call center:

Chapter 9, Problem 75PS, Call centers today play an important role in managing day-to-day business communication with

a. At the 0.05 level of significance, is there evidence that the population mean time to answer calls is less than 20 seconds?

b. What assumption about the population distribution is needed is order to conduct the t test in (a)?

c. Construct a histogram, boxplot, or normal probability plot to evaluate the assumption made in (b).

d. Do you think that the assumption needed in order to conduct the t test in (a) is valid? Explain.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

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Chapter 9, Problem 74PS

Chapter 9, Problem 76PS

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Chapter 9 Solutions

Basic Business Statistics, Student Value Edition

Ch. 9 - If you use a 0.005 level of significance in a...Ch. 9 - If you use a 0.05 level of significance in a...Ch. 9 - If you use a 0.10 level of significance in a...Ch. 9 - If you use a 0.01 level of significance in a...Ch. 9 - What is your decision in problem 9.4 if...Ch. 9 - What is the p -value if, in a two-tail hypothesis...Ch. 9 - In problem 9.6, what is your statistical decision...Ch. 9 - What is the p-value if, in a two -tail hypothesis...Ch. 9 - In the U.S. legal system, a defendant is presumed...Ch. 9 - Suppose the defendant in Problem 9.9 is presumed...

Ch. 9 - Many consumer groups feel that U.S. Food and Drug...Ch. 9 - As a result of complaints from both students and...Ch. 9 - Do business senior at your school prepare for...Ch. 9 - The quality- control manager at a light emitting...Ch. 9 - Suppose that in problem 9.14, the standard...Ch. 9 - A bottled water distributor wants to determine...Ch. 9 - Suppose that in Problem 9.16, the standard...Ch. 9 - If, In a sample of n=16 selected from a normal...Ch. 9 - In Problem 9.18, how many degrees of freedom does...Ch. 9 - In Problem 9.18, 9.19, what are the Critical...Ch. 9 - In, Problem 9.18, 9.19, and 9.20, what is your...Ch. 9 - If, in a sample of n=16 selected from a...Ch. 9 - If, in a sample of n=160 selected from a...Ch. 9 - You are the manager of a restaurant for a...Ch. 9 - A manufacturer of chocolate candies uses machines...Ch. 9 - A marketing researcher wants to estimate the mean...Ch. 9 - The U.S. Department of Transportation requires...Ch. 9 - The file FastFood contains the amount that a...Ch. 9 - An insurance company has the business objective of...Ch. 9 - The following data (in Drink) represent the amount...Ch. 9 - One of the major measures of the quality of...Ch. 9 - A manufacturing company produces steel housings...Ch. 9 - One operation of a steel mill is to cut pieces of...Ch. 9 - In Problem 3.69 on page 156, you were introduced...Ch. 9 - We Are Social and Hootsuite reported that the...Ch. 9 - In a one-tail hypothesis test where you reject H0...Ch. 9 - In Problem 9.36, what is your statistical decision...Ch. 9 - In a one-tail hypothesis test where you reject H0...Ch. 9 - In Problem 9.38, what is your statistical decision...Ch. 9 - In a one-tail hypothesis test where you reject H0...Ch. 9 - In Problem 9.40, what is your statistical decision...Ch. 9 - In a one-tail hypothesis test where you reject H0...Ch. 9 - In Problem 9.42, what is your statistical decision...Ch. 9 - In a one-tail hypothesis test where you reject H0...Ch. 9 - In Problem 9.44, what is your statistical decision...Ch. 9 - The Washington Metropolitan Area Transit Authority...Ch. 9 - CarMD reports that after two years of flat U.S....Ch. 9 - Patient waiting is a common phenomenon the...Ch. 9 - You are the manager of a restaurant that delivers...Ch. 9 - A Survey of nonprofit organization showed that...Ch. 9 - The population mean waiting time to check out of a...Ch. 9 - If, a random sample of 400 items, 88 are...Ch. 9 - In Problem 9.52, if the null hypothesis is that 20...Ch. 9 - In Problem 9.52 and 9.53, suppose you are testing...Ch. 9 - According to a recent National Association of...Ch. 9 - The worldwide market share for the Chrome web...Ch. 9 - One of the issues facing organizations Is...Ch. 9 - What are companiesâ€™ biggest obstacles to...Ch. 9 - A cellphone provider has the business objective of...Ch. 9 - Actuation Consulting conducted a global survey of...Ch. 9 - What is the difference between a null hypothesis,...Ch. 9 - What is the difference between a Type I error and...Ch. 9 - What is meant by the power of a test?Ch. 9 - What is the difference between a one -tail test...Ch. 9 - What is meant by a p-value?Ch. 9 - How can a confidence interval estimate for the...Ch. 9 - What is the six-step critical value approach to...Ch. 9 - What is the five-step p-value approach to...Ch. 9 - In hypothesis testing, the common level of...Ch. 9 - Financial institutions utilize prediction models...Ch. 9 - IAB conducted a study of 821 U.S. adults to...Ch. 9 - The owner of a speciality coffee shop wants to...Ch. 9 - An auditor for a government agency was assigned...Ch. 9 - A bank branch located in a commercial district of...Ch. 9 - Call centers today play an important role in...Ch. 9 - An important quality characteristic used by the...Ch. 9 - Studies conducted by the manufacturer of Boston...Ch. 9 - The manufacturer of Boston and Vermont asphalt...Ch. 9 - Referring to the results of problems 9.76 through...

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Solution Summary: The author explains the five steps of the p-value approach to determine whether the mean time to answer the calls is less than 20 seconds.

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Chapter 9 Solutions