Statistics for Business and Economics (13th Edition)
13th Edition
ISBN: 9780134506593
Author: James T. McClave, P. George Benson, Terry Sincich
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 8.3, Problem 8.37ACI
Taking “power naps” during work breaks. Lack of sleep costs companies about $13 billion a year in lost productivity, according to the National Sleep Foundation. In recognition of this problem, many companies now make quiet rooms available for employees to take “power naps” during work breaks (U.S. News & World Report, November 15, 2010). Consider a major airline that encourages reservation agents to nap during their breaks. The accompanying table lists the number of complaints received about each of a sample of 10 reservation agents during the 6 months before naps were encouraged and during the 6 months after the policy change.
- a. Do the data present sufficient evidence to conclude that the new napping policy reduced the
mean number of customer complaints about reservation agents? Test using α: — .05. - b. What assumptions must hold to ensure the validity of the test?
- c. What variables, no: controlled in the study, could lead to an invalid conclusion?
| Operator | Before Policy | After Policy |
| 1 | 10 | 5 |
| 2 | 3 | 0 |
| 3 | 16 | 7 |
| 4 | 11 | 4 |
| 5 | 8 | 6 |
| 6 | 2 | 4 |
| 7 | 1 | 2 |
| 8 | 14 | 3 |
| 9 | 5 | 5 |
| 10 | 6 | 1 |
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Write codes to perform the functions in each of these cases
i.
ii.
Apply cd command to tell STATA the filepath associated with
your "favorite folder" (use the same name for the favorite folder
that we have been using in class)
Apply log using command to tell stata that you are creating a log
file to record the codes and the outcomes of these codes. Make
sure your log file is called loghwa1_W25.smcl. Do not forget to
include the replace option.
iii. Get help for the "regress" command & include a screenshot of
the outcome of this code
iv.
V.
Open a stata file stored in STATA memory called pop2000.dta
Continue from question iv. Save this file in your favorite folder
(current working directory) using a different name & a replace
option
Are there any unusually high or low pH levels in this sample of wells?
0
n
AM
RIES
s of
of
10
m
Frequency
40
Frequency
20
20
30
10
You make two histograms from two different
data sets (see the following figures), each
one containing 200 observations. Which of
the histograms has a smaller spread: the first
or the second?
40
30
20
10
0
20
40
60
0
20
20
40
60
60
80
80
100
80
100
Chapter 8 Solutions
Statistics for Business and Economics (13th Edition)
Ch. 8.2 - The purpose of this exercise is to compare the...Ch. 8.2 - Prob. 8.2LMCh. 8.2 - In order to compare the means of two populations,...Ch. 8.2 - Prob. 8.4LMCh. 8.2 - Prob. 8.5LMCh. 8.2 - Prob. 8.6LMCh. 8.2 - Independent random samples from normal populations...Ch. 8.2 - Two independent random samples nave been...Ch. 8.2 - Independent random samples of n1 = 233 and n2 =...Ch. 8.2 - Independent random samples from approximately...
Ch. 8.2 - Independent random samples selected from two...Ch. 8.2 - Lobster trap placement. Refer to the Bulletin of...Ch. 8.2 - Last name and acquisition timing. The speed with...Ch. 8.2 - Shared leadership in airplane crews. Human Factors...Ch. 8.2 - Performance-based logistics. Refer to the Journal...Ch. 8.2 - Drug content assessment. Refer to Exercise 4.123...Ch. 8.2 - Buy-side vs. sell-side analysts earnings...Ch. 8.2 - Homework assistance for accounting students. How...Ch. 8.2 - Comparing taste-test rating protocols....Ch. 8.2 - Producer willingness to supply biomass. The...Ch. 8.2 - Does rudeness really matter in the workplace?...Ch. 8.2 - Prob. 8.22ACICh. 8.2 - Is honey a cough remedy? Refer to the Archives of...Ch. 8.2 - Gender diversity of board of directors. The gender...Ch. 8.2 - Prob. 8.25ACACh. 8.3 - A paired difference experiment produced the...Ch. 8.3 - A paired difference experiment yielded nd pairs of...Ch. 8.3 - The data for a random sample of six paired...Ch. 8.3 - The data for a random sample of 10 paired...Ch. 8.3 - A paired difference experiment yielded the...Ch. 8.3 - Summer weight-loss camp. Camp Jump Start is an...Ch. 8.3 - Performance ratings of government agencies. The...Ch. 8.3 - Twinned drill holes. A traditional method of...Ch. 8.3 - Prob. 8.34ACBCh. 8.3 - I am not selling anything surveys. To improve...Ch. 8.3 - Consumers attitudes toward advertising. The two...Ch. 8.3 - Taking power naps during work breaks. Lack of...Ch. 8.3 - Acidity of mouthwash. Acid has been found to be a...Ch. 8.3 - Solar energy generation along highways. The...Ch. 8.3 - Impact of red light cameras on car crashes. To...Ch. 8.3 - Prob. 8.41ACICh. 8.3 - Alcoholic fermentation in wines. Determining...Ch. 8.4 - Consider making an inference about p1 p2, where...Ch. 8.4 - For each of the following values of , find the...Ch. 8.4 - Prob. 8.45LMCh. 8.4 - Prob. 8.46LMCh. 8.4 - Prob. 8.47LMCh. 8.4 - Prob. 8.48LMCh. 8.4 - The winners curse in auction bidding. In auction...Ch. 8.4 - Prob. 8.50ACBCh. 8.4 - Prob. 8.51ACBCh. 8.4 - Web survey response rates. Response rates to Web...Ch. 8.4 - Hospital administration of malaria patients. One...Ch. 8.4 - Traffic sign maintenance. The Federal Highway...Ch. 8.4 - Salmonella in produce. Salmonella infection is the...Ch. 8.4 - Angioplastys benefits challenged. More than 1...Ch. 8.4 - Entrepreneurial careers of MBA alumni. Are African...Ch. 8.4 - Predicting software defects. Refer to the PROMISE...Ch. 8.4 - Prob. 8.59ACICh. 8.4 - Religious symbolism in TV commercials. Gonzaga...Ch. 8.5 - Assuming that n1 = n2, find the sample sizes...Ch. 8.5 - Find the appropriate values of n1 and n2 (assume...Ch. 8.5 - Suppose you want to estimate the difference...Ch. 8.5 - Enough money has been budgeted to collect...Ch. 8.5 - Last name and acquisition timing. Refer to the...Ch. 8.5 - Homework assistance for accounting students. Refer...Ch. 8.5 - Vulnerability of relying party Web sites. Refer to...Ch. 8.5 - Conducting a political poll. A pollster wants to...Ch. 8.5 - Shared leadership in airplane crews. Refer to the...Ch. 8.5 - Solar energy generation along highways. Refer to...Ch. 8.5 - Angioplastys benefits challenged. Refer to the...Ch. 8.5 - Traffic sign maintenance. Refer to the Journal of...Ch. 8.6 - Use Tables V, VI, VII, and VIII in Appendix D to...Ch. 8.6 - Given v1 and v2, find the following probabilities:...Ch. 8.6 - For each of the following cases, identify the...Ch. 8.6 - For each of the following cases, identify the...Ch. 8.6 - Specify the appropriate rejection region for...Ch. 8.6 - Independent random samples were selected from each...Ch. 8.6 - Independent random samples were selected from each...Ch. 8.6 - Lobster trap placement. Refer to the Bulletin of...Ch. 8.6 - Prob. 8.81ACBCh. 8.6 - Mental health of workers and the unemployed. A...Ch. 8.6 - Drug content assessment Refer to Exercise 8.16 (p....Ch. 8.6 - Last name and acquisition timing. Refer to the...Ch. 8.6 - Prob. 8.85ACICh. 8.6 - Oil content of fried sweet potato chips. Refer to...Ch. 8.6 - Shopping vehicle and judgment. Refer to the...Ch. 8.6 - Is honey a cough remedy? Refer to the Archives of...Ch. 8 - List the assumptions necessary for each of the...Ch. 8 - Two independent random samples were selected from...Ch. 8 - Independent random samples were selected from two...Ch. 8 - Independent random samples were selected from two...Ch. 8 - Two independent random samples are taken from two...Ch. 8 - A random sample of five pairs of observations were...Ch. 8 - Prob. 8.95ACBCh. 8 - Prob. 8.96ACBCh. 8 - Prob. 8.97ACBCh. 8 - Hull failures of oil tankers. Refer to the Marine...Ch. 8 - Effectiveness of teaching software. The U.S....Ch. 8 - Durability of shock absorbers. A manufacturer of...Ch. 8 - NHTSA new car crash tests. Refer to the National...Ch. 8 - Diamonds sold at retail. Refer to the data for 308...Ch. 8 - Childrens recall of TV ads. A study examined...Ch. 8 - Is steak your favorite barbeque food? July is...Ch. 8 - Planning habits survey. American Demographics...Ch. 8 - Turnover rates in the United States and Japan....Ch. 8 - Smartphone usage differs by gender. The role of...Ch. 8 - Life expectancies of working women and housewives....Ch. 8 - Comparing purchasers and nonpurchasers of...Ch. 8 - Prob. 8.110ACICh. 8 - Racial profiling by the LAPD. Racial profiling is...Ch. 8 - State SAT scores. Refer to Exercise 2.27 (p. 60)...Ch. 8 - Rat damage to sugarcane fields. Poisons are used...Ch. 8 - Environmental impact study. Some power plants are...Ch. 8 - Instrument precision. When new instruments are...Ch. 8 - Cooling method for gas turbines. Refer to the...Ch. 8 - Average housing space per person. Even though...Ch. 8 - Positive spillover effects from self-managed work...Ch. 8 - Impact of gender on advertising. How does gender...Ch. 8 - Salaries of postgraduates. Refer to the Economics...Ch. 8 - Gambling in public high schools. With the rapid...Ch. 8 - CareerBank.com annual salary survey....Ch. 8 - Facility layout study. Facility layout and...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- TIP the aren't, the data are not sym 11 Suppose that the average salary at a certain company is $100,000, and the median salary is $40,000. a. What do these figures tell you about the shape of the histogram of salaries at this company? b. Which measure of center is more appro- priate here? c. Suppose that the company goes through a salary negotiation. How can people on each side use these summary statistics to their advantage? 6360 be 52 PART 1 Getting Off to a Statistically Significant Sarrow_forward12 Suppose that you know that a data set is skewed left, and you know that the two measures of center are 19 and 38. Which figure is the mean and which is the median?arrow_forwardy of 45 home- televisions u find that 010020 le own one, ee, and 1 owns y histogram of 4 Suppose that you have a loaded die. You roll it several times and record the outcomes, which are shown in the following figure. Histogram for Loaded Die 444% 34.00 48% 6% 2% Frequency 20 20 15 155 10 5- ம 0 1 2 3 4 Outcome 5 6 a. Make a relative frequency histogram of these results. b. You can make a relative frequency histo- gram from a frequency histogram; can you go the other direction?arrow_forward
- Calculate the mean for Study Hours and Test Scores. Compute the covariance between the two variables using the formula: Calculate the standard deviation for Study Hours (X) and Test Scores (Y). Determine the correlation coefficient Interpret the results: What does the calculated r-value indicate about the relationship between study hours and test scores?arrow_forwardFor unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of months unemployed and the values in the second column show the corresponding number of unemployed persons. Months Unemployed Number Unemployed 1 1029 2 1686 3 2269 4 2675 5 3487 6 4652 7 4145 8 3587 9 2325 10 1120 Let x be a random variable indicating the number of months a person is unemployed. a. Use the data to develop an empirical discrete probability distribution for x (to 4 decimals). (x) f(x) 1 2 3 4 5 6 7 8 9 10 b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution. The input in the box below will not be graded, but may be reviewed and considered by your instructor. blank c. What is the probability that a…arrow_forwardWest Virginia has one of the highest divorce rates in the nation, with an annual rate of approximately 5 divorces per 1000 people (Centers for Disease Control and Prevention website, January 12, 2012). The Marital Counseling Center, Inc. (MCC) thinks that the high divorce rate in the state may require them to hire additional staff. Working with a consultant, the management of MCC has developed the following probability distribution for x = the number of new clients for marriage counseling for the next year. Excel File: data05-19.xls x 10 f(x) .05 20 30 .10 .10 40 .20 50 60 .35 .20 a. Is this probability distribution valid? - Select your answer- Explain. f(x) Σf(x) Select your answer Select your answer b. What is the probability MCC will obtain more than 30 new clients (to 2 decimals)? c. What is the probability MCC will obtain fewer than 20 new clients (to 2 decimals)? d. Compute the expected value and variance of x. Expected value Variance clients per year squared clients per yeararrow_forward
- For unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of months unemployed and the values in the second column show the corresponding number of unemployed persons. Months Unemployed Number Unemployed 1 1029 2 1686 3 2269 4 2675 5 3487 6 4652 7 4145 8 3587 9 2325 10 1120 Let x be a random variable indicating the number of months a person is unemployed. a. Use the data to develop an empirical discrete probability distribution for x (to 4 decimals). (x) f(x) 1 2 3 4 5 6 7 8 9 10 b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution. The input in the box below will not be graded, but may be reviewed and considered by your instructor. c. What is the probability that a person…arrow_forwardIn Gallup's Annual Consumption Habits Poll, telephone interviews were conducted for a random sample of 1014 adults aged 18 and over. One of the questions was "How many cups of coffee, if any, do you drink on an average day?" The following table shows the results obtained (Gallup website, August 6, 2012). Excel File: data05-23.xls Number of Cups per Day Number of Responses 0 365 264 193 3 4 or more 91 101 Define a random variable x = number of cups of coffee consumed on an average day. Let x = 4 represent four or more cups. Round your answers to four decimal places. a. Develop a probability distribution for x. x 0 1 2 3 4 f(x) b. Compute the expected value of x. cups of coffee c. Compute the variance of x. cups of coffee squared d. Suppose we are only interested in adults that drink at least one cup of coffee on an average day. For this group, let y = the number of cups of coffee consumed on an average day. Compute the expected value of y. Compare it to the expected value of x. The…arrow_forwardIn Gallup's Annual Consumption Habits Poll, telephone interviews were conducted for a random sample of 1014 adults aged 18 and over. One of the questions was "How many cups of coffee, if any, do you drink on an average day?" The following table shows the results obtained (Gallup website, August 6, 2012). Excel File: data05-23.xls Number of Cups per Day Number of Responses 0 365 264 193 2 3 4 or more 91 101 Define a random variable x = number of cups of coffee consumed on an average day. Let x = 4 represent four or more cups. Round your answers to four decimal places. a. Develop a probability distribution for x. x 0 1 2 3 f(x) b. Compute the expected value of x. cups of coffee c. Compute the variance of x. cups of coffee squared d. Suppose we are only interested in adults that drink at least one cup of coffee on an average day. For this group, let y = the number of cups of coffee consumed on an average day. Compute the expected value of y. Compare it to the expected value of x. The…arrow_forward
- A technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency. Develop a probability distribution for the duration of a service call. Duration of Call x f(x) 1 2 3 4 Which of the following probability distribution graphs accurately represents the data set? Consider the required conditions for a discrete probability function, shown below.Does this probability distribution satisfy equation (5.1)?Does this probability distribution satisfy equation (5.2)? What is the probability a service call will take three hours? A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today?arrow_forwardA psychologist determined that the number of sessions required to obtain the trust of a new patient is either 1, 2, or 3. Let x be a random variable indicating the number of sessions required to gain the patient's trust. The following probability function has been proposed. x f(x) for x = 1, 2, or 3 a. Consider the required conditions for a discrete probability function, shown below. f(x) ≥0 Σf(x) = 1 (5.1) (5.2) Does this probability distribution satisfy equation (5.1)? Select Does this probability distribution satisfy equation (5.2)? Select b. What is the probability that it takes exactly 2 sessions to gain the patient's trust (to 3 decimals)? c. What is the probability that it takes at least 2 sessions to gain the patient's trust (to 3 decimals)?arrow_forwardA technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency. Develop a probability distribution for the duration of a service call. Which of the following probability distribution graphs accurately represents the data set? Consider the required conditions for a discrete probability function, shown below.Does this probability distribution satisfy equation (5.1)?Does this probability distribution satisfy equation (5.2)? What is the probability a service call will take three hours? A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Sampling Methods and Bias with Surveys: Crash Course Statistics #10; Author: CrashCourse;https://www.youtube.com/watch?v=Rf-fIpB4D50;License: Standard YouTube License, CC-BY
Statistics: Sampling Methods; Author: Mathispower4u;https://www.youtube.com/watch?v=s6ApdTvgvOs;License: Standard YouTube License, CC-BY