Question: There has been a trend toward less

> The data from exercise 2 follow. a. Compute the mean square error using equation (14.15). b. Compute the standard error of the estimate using equation (14.16). c. Compute the estimated standard deviation of b1 using equation (14.18). d. Use the t test

> The data from exercise 1 follow. a. Compute the mean square error using equation (14.15). b. Compute the standard error of the estimate using equation (14.16). c. Compute the estimated standard deviation of b1 using equation (14.18). d. Use the t test

> The following data were used to investigate the relationship between the number of cars in service (1000s) and the annual revenue ($millions) for six smaller car rental companies (Auto Rental News website). With x = cars in service (1000s) and y = annu

> An important application of regression analysis in accounting is in the estimation of cost. By collecting data on volume and cost and using the least squares method to develop an estimated regression equation relating volume and cost, an accountant can e

> At 95% confidence, how large a sample should be taken to obtain a margin of error of .03 for the estimation of a population proportion? Assume that past data are not available for developing a planning value for p*.

> Bicycling, the world’s leading cycling magazine, reviews hundreds of bicycles throughout the year. Their “Road-Race” category contains reviews of bikes used by riders primarily interested in racing. O

> Given are five observations for two variables, x and y. a. Develop a scatter diagram for these data. b. What does the scatter diagram developed in part (a) indicate about the relationship between the two variables? c. Try to approximate the relationshi

> In exercise 7 a sales manager collected the following data on x = annual sales and y = years of experience. The estimated regression equation for these data is ŷ = 80 + 4x. a. Compute SST, SSR, and SSE. b. Compute the coefficient of deter

> The following data show the brand, price ($), and the overall score for six stereo headphones that were tested by Consumer Reports (Consumer Reports website). The overall score is based on sound quality and effectiveness of ambient noise reduction. Score

> The data from exercise 3 follow. The estimated regression equation for these data is ŷ = 7.6 + .9x. What percentage of the total sum of squares can be accounted for by the estimated regression equation? What is the value of the sample cor

> The data from exercise 2 follow. The estimated regression equation for these data is ŷ = 68 − 3x. a. Compute SSE, SST, and SSR. b. Compute the coefficient of determination r2. Comment on the goodness of fit. c. Compute t

> The data from exercise 1 follow. The estimated regression equation for these data is ŷ = .20 + 2.60x. a. Compute SSE, SST, and SSR using equations (14.8), (14.9), and (14.10). b. Compute the coefficient of determination r2. Comment on the

> A large city hospital conducted a study to investigate the relationship between the number of unauthorized days that employees are absent per year and the distance (miles) between home and work for the employees. A sample of 10 employees was selected and

> To the Internal Revenue Service, the reasonableness of total itemized deductions depends on the taxpayer’s adjusted gross income. Large deductions, which include charity and medical deductions, are more reasonable for taxpayers with lar

> In June of 2016, Yahoo Finance reported the beta value for Coca-Cola was .82 (Yahoo Finance website). Betas for individual stocks are determined by simple linear regression. The dependent variable is the total return for the stock, and the independent va

> In a survey, the planning value for the population proportion is p* = .35. How large a sample should be taken to provide a 95% confidence interval with a margin of error of .05?

> To help consumers in purchasing a laptop computer, Consumer Reports calculates an overall test score for each computer tested based upon rating factors such as ergonomics, portability, performance, display, and battery life. Higher overall scores indicat

> For a particular red wine, the following data show the auction price for a 750-milliliter bottle and the age of the wine in June of 2016 (WineX website). a. Develop a scatter diagram for these data with age as the independent variable. b. What does the

> Given are five observations for two variables, x and y. a. Develop a scatter diagram for these data. b. What does the scatter diagram developed in part (a) indicate about the relationship between the two variables? c. Try to approximate the relationshi

> To study the effect of temperature on yield in a chemical process, five batches were produced at each of three temperature levels. The results follow. Construct an analysis of variance table. Use a .05 level of significance to test whether the temperatur

> Refer to the NCP data in Table 13.4. Set up the ANOVA table and test for any significant difference in the mean examination score for the three plants. Use α = .05. Table 13.4:

> Three different methods for assembling a product were proposed by an industrial engineer. To investigate the number of units assembled correctly with each method, 30 employees were randomly selected and randomly assigned to the three proposed methods in

> Develop the analysis of variance computations for the following completely randomized design. At α = .05, is there a significant difference between the treatment means?

> In a completely randomized design, 12 experimental units were used for the first treatment, 15 for the second treatment, and 20 for the third treatment. Complete the following analysis of variance. At a .05 level of significance, is there a significant d

> In an experiment designed to test the output levels of three different treatments, the following results were obtained: SST = 400, SSTR = 150, ηT = 19. Set up the ANOVA table and test for any significant difference between the mean output levels of the t

> A study reported in The Accounting Review examined the separate and joint effects of two levels of time pressure (low and moderate) and three levels of knowledge (naive, declarative, and procedural) on key word selection behavior in tax research. Subject

> A simple random sample of 800 elements generates a sample proportion p̅ = .70. a. Provide a 90% confidence interval for the population proportion. b. Provide a 95% confidence interval for the population proportion.

> As part of a study designed to compare hybrid and similarly equipped conventional vehicles, Consumer Reports tested a variety of classes of hybrid and all-gas model cars and sport utility vehicles (SUVs). The following data show the miles-per-gallon rati

> An amusement park studied methods for decreasing the waiting time (minutes) for rides by loading and unloading riders more efficiently. Two alternative loading/unloading methods have been proposed. To account for potential differences due to the type of

> Based on a 2018 study, the average elapsed time between when a user navigates to a website on a mobile device until its main content is available was 14.6 seconds. This is more than a 20% increase from 2017 (searchenginejournal.com, https://www.searcheng

> Refer to exercise 2. a. What hypotheses are implied in this problem? b. At the α = .05 level of significance, can we reject the null hypothesis in part (a)? Explain. Exercise 2: In a completely randomized design, seven experimental units w

> The calculations for a factorial experiment involving four levels of factor A, three levels of factor B, and three replications resulted in the following data: SST = 280, SSA = 26, SSB = 23, SSAB = 175. Set up the ANOVA table and test for any significant

> A factorial experiment involving two levels of factor A and three levels of factor B resulted in the following data. Test for any significant main effects and any interaction. Use α = .05.

> In 2018, consumer goods giant Procter and Gamble (P&G) had more than 20 brands with more than $1 billion in annual sales (P&G website, https://us.pg.com/). How does a company like P&G create so many successful consumer products? P&G effec

> The Scholastic Aptitude Test (SAT) contains three areas: critical reading, mathematics, and writing. Each area is scored on an 800-point scale. A sample of SAT scores for six students follows. a. Using a .05 level of significance, do students perform d

> Are there differences in airfare depending on which travel agency website you utilize? The following data were collected on travel agency websites on July 9, 2018. The following table contains the prices in U.S. dollars for a one-way ticket between the c

> An automobile dealer conducted a test to determine if the time in minutes needed to complete a minor engine tune-up depends on whether a computerized engine analyzer or an electronic analyzer is used. Because tune-up time varies among compact, intermedia

> A simple random sample of 400 individuals provides 100 Yes responses. a. What is the point estimate of the proportion of the population that would provide Yes responses? b. What is your estimate of the standard error of the proportion,σp? c. Compute the

> The following sample data are from a normal population: 10, 8, 12, 15, 13, 11, 6, 5. a. What is the point estimate of the population mean? b. What is the point estimate of the population standard deviation? c. With 95% confidence, what is the margin of e

> An experiment has been conducted for four treatments with eight blocks. Complete the following analysis of variance table. Use α = .05 to test for any significant differences.

> The following data were obtained for a randomized block design involving five treatments and three blocks: SST = 430, SSTR = 310, SSBL = 85. Set up the ANOVA table and test for any significant differences. Use α = .05.

> Consider the experimental results for the following randomized block design. Make the calculations necessary to set up the analysis of variance table. Use α = .05 to test for any significant differences.

> The International League of Triple-A minor league baseball consists of 14 teams organized into three divisions: North, South, and West. The following data show the average attendance for the 14 teams in the International League. Also shown are the teams&

> In a completely randomized design, seven experimental units were used for each of the five levels of the factor. Complete the following ANOVA table.

> Refer to exercise 18. Use the Bonferroni adjustment to test for a significant difference between all pairs of means. Assume that a maximum overall experimentwise error rate of .05 is desired. Exercise 18: To test for any significant difference in the nu

> To test for any significant difference in the number of hours between breakdowns for four machines, the following data were obtained. a. At the α = .05 level of significance, what is the difference, if any, in the population mean times a

> In the digital age of marketing, special care must be taken to make sure that programmatic ads appearing on websites align with a company’s strategy, culture and ethics. For example, in 2017, Nordstrom, Amazon and Whole Foods each faced

> Refer to exercise 15. Use Fisher’s LSD procedure to develop a 95% confidence interval estimate of the difference between the means for manufacturer 1 and manufacturer 2. Exercise 15: To test whether the mean time needed to mix a batch

> To test whether the mean time needed to mix a batch of material is the same for machines produced by three manufacturers, the Jacobs Chemical Company obtained the following data on the time (in minutes) needed to mix the material. a. Use these data to

> The following data are from a completely randomized design. In the following calculations, use α = .05. / a. Use analysis of variance to test for a significant difference among the means of the three treatments. b. Use Fisher’s LSD procedure to determi

> The following data are from a completely randomized design. a. At the α = .05 level of significance, can we reject the null hypothesis that the means of the three treatments are equal? b. Use Fisher’s LSD procedure to te

> The Consumer Reports Restaurant Customer Satisfaction Survey is based upon 148,599 visits to full-service restaurant chains (Consumer Reports website, https://www.consumerreports.org/cro/restaurants/buying-guide/index.htm). One of the variables in the st

> How long it takes paint to dry can have an impact on the production capacity of a business. In May 2018, Deal’s Auto Body & Paint in Prescott, Arizona, invested in a paint-drying robot to speed up its process (The Daily Courier webs

> Auditors must make judgments about various aspects of an audit on the basis of their own direct experience, indirect experience, or a combination of the two. In a study, auditors were asked to make judgments about the frequency of errors to be found in a

> The following data are from a completely randomized design. a. Compute the sum of squares between treatments. b. Compute the mean square between treatments. c. Compute the sum of squares due to error. d. Compute the mean square due to error. e. Set up

> The following table contains observed frequencies for a sample of 200. Test for independence of the row and column variables using α = .05.

> The Ertl Company is well known for its high-quality die-cast metal alloy toy replicas of tractors and other farm equipment. As part of a periodic procurement evaluation, Ertl is considering purchasing parts for a toy tractor line from three different sup

> Social media is becoming more and more popular around the world. Statista.com provides estimates of the number of social media users in various countries in 2017 as well as the projections for 2022. Assume that the results for surveys in the United Kingd

> 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

> Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time devoted to previews is too long. A preliminary sample con

> The Carnegie Classification of Institutes of Higher Education categorizes colleges and universities on the basis of their research and degree-granting activities. Universities that grant doctoral degrees are placed into one of three classifications: mode

> Benson Manufacturing is considering ordering electronic components from three different suppliers. The suppliers may differ in terms of quality in that the proportion or percentage of defective components may differ among the suppliers. To evaluate the p

> The sample data below represent the number of late and on time flights for Delta, United, and US Airways. Airline a. Formulate the hypotheses for a test that will determine if the population proportion of late flights is the same for all three airlines

> The manager at a Whole Foods Market is responsible for managing store inventory. The mathematical models that she uses to determine how much inventory to stock rely on product demand being normally distributed. In particular, the weekly demand of srirach

> Bob Feller, an Iowa farmer, has recorded the daily high temperatures during the same five-day stretch in May over the past five years. Bob is interested in whether this data suggests that the daily high temperature obeys a normal distribution. Use &Icirc

> The National Highway Traffic Safety Administration reported the percentage of traffic accidents occurring each day of the week. Assume that a sample of 420 accidents provided the following data. a. Conduct a hypothesis test to determine if the proportio

> The Wall Street Journal’s Shareholder Scoreboard tracks the performance of 1000 major U.S. companies. The performance of each company is rated based on the annual total return, including stock price changes and the reinvestment of divid

> Mars, Inc. manufactures M&€™s, one of the most popular candy treats in the world. The milk chocolate candies come in a variety of colors including blue, brown, green, orange, red, and yellow. The overall proportions for the colors are .24 b

> During the first 13 weeks of the television season, the Saturday evening 8 p.m. to 9 p.m. audience proportions were recorded as ABC 29%, CBS 28%, NBC 25%, and independents 18%. A sample of 300 homes two weeks after a Saturday night schedule revision yiel

> The following data are believed to have come from a normal distribution. Use the goodness of fit test and α = .05 to test this claim.

> Many medical professionals believe that eating too much red meat increases the risk of heart disease and cancer. Suppose you would like to conduct a survey to determine the yearly consumption of beef by a typical American and want to use 3 pounds as the

> Reconsider the observed frequencies in exercise 1 a. Compute the sample proportion for each population. b. Use the multiple comparison procedure to determine which population proportions differ significantly. Use a .05 level of significance. Exercise 1:

> Test the following hypotheses by using the χ2 goodness of fit test. H0: pA = .40, pB = .40, and pC = .20 Ha: The population proportions are not pA = .40, pB = .40, and pC = .20 A sample of size 200 yielded 60 in category A, 120 in category B, and 20 in c

> On a television program, two movie critics provide their reviews of recent movies and discuss. It is suspected that these hosts deliberately disagree in order to make the program more interesting for viewers. Each movie review is categorized as Pro (&aci

> The National Sleep Foundation used a survey to determine whether hours of sleep per night are independent of age. A sample of individuals was asked to indicate the number of hours of sleep per night with categorical options: fewer than 6 hours, 6 to 6.9

> The race for the 2013 Academy Award for Actress in a Leading Role was extremely tight, featuring several worthy performances. The nominees were Jessica Chastain for Zero Dark Thirty, Jennifer Lawrence for Silver Linings Playbook, Emmanuelle Riva for Amou

> The Wall Street Journal Annual Corporate Perceptions Study surveyed readers and asked how they rated the quality of management and the reputation of the company for more than 250 worldwide corporations. Both the quality of management and the reputation o

> A J. D. Power and Associates vehicle quality survey asked new owners a variety of questions about their recently purchased automobile. One question asked for the owner’s rating of the vehicle using categorical responses of average, outs

> A Deloitte employment survey asked a sample of human resource executives how their company planned to change its workforce over the next 12 months. A categorical response variable showed three options: The company plans to hire and add to the number of e

> A Bloomberg Businessweek subscriber study asked, “In the past 12 months, when traveling for business, what type of airline ticket did you purchase most often?” A second question asked if the type of airline ticket purc

> Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $45,000 and $60,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. What

> The following table contains observed frequencies for a sample of 240. Test for independence of the row and column variables using α = .05.

> Use the sample data below to test the hypotheses H0: p1 = p2 = p3 Ha: Not all population proportions are equal where pi is the population proportion of Yes responses for population i. Using a .05 level of significance, what is the p-value and what is you

> The competitive advantage of small American factories such as Tolerance Contract Manufacturing lies in their ability to produce parts with highly narrow requirements, or tolerances, that are typical in the aerospace industry. Consider a product with spec

> Consider a day when the Dow Jones Industrial Average went up 149.82 points. The following table shows the stock price changes for a sample of 12 companies on that day. a. Compute the sample variance for the daily price change. b. Compute the sample sta

> In 2017, Americans spent a record-high $9.1 billion on Halloween- related purchases (the balance website, https://www.thebalance.com /halloween-spending-statistics-facts-and-trends-3305716). Sample data showing the amount, in dollars, 16 adults spent on

> To analyze the risk, or volatility, associated with investing in General Electric common stock, consider a sample of the eight quarterly percent total returns. The percent total return includes the stock price change plus the dividend payment for the qua

> In 2018, Mike Krzyewski and John Calipari topped the list of highest-paid college basketball coaches (Sports Illustrated website, https://www.si.com/college-basketball/2018/03/01/highest-paid-college-basketball -coaches-salaries-mike-krzyewski-john-calip

> Amazon.com is testing the use of drones to deliver packages for same-day delivery. In order to quote narrow time windows, the variability in delivery times must be sufficiently small. Consider a sample of 24 drone deliveries with a sample variance of s2

> A sample of 16 items provides a sample standard deviation of 9.5. Test the following hypotheses using α = .05. What is your conclusion? Use both the p-value approach and the critical value approach.

> A research hypothesis is that the variance of stopping distances of automobiles on wet pavement is substantially greater than the variance of stopping distances of automobiles on dry pavement. In the research study, 16 automobiles traveling at the same s

> The U.S. Energy Information Administration (US EIA) reported that the average price for a gallon of regular gasoline is $2.94. The US EIA updates its estimates of average gas prices on a weekly basis. Assume the standard deviation is $.25 for the price o

> Battery life is an important issue for many smartphone owners. Public health studies have examined “low-battery anxiety” and acute anxiety called nomophobia that results when a smartphone user’s phone

> On the basis of data provided by a Romac salary survey, the variance in annual salaries for senior partners in public accounting firms is approximately 2.1 and the variance in annual salaries for managers in public accounting firms is approximately 11.1.

> A sample of 20 items provides a sample standard deviation of 5. a. Compute the 90% confidence interval estimate of the population variance. b. Compute the 95% confidence interval estimate of the population variance. c. Compute the 95% confidence interva

> The variance in a production process is an important measure of the quality of the process. A large variance often signals an opportunity for improvement in the process by finding ways to reduce the process variance. Jelly Belly Candy Company is testing

> Barron’s has collected data on the top 1000 financial advisers. Merrill Lynch and Morgan Stanley have many of their advisers on this list. A sample of 16 of the Merrill Lynch advisers and 10 of the Morgan Stanley advisers showed that the advisers managed

> In its 2016 Auto Reliability Survey, Consumer Reports asked subscribers to report their maintenance and repair costs. Most individuals are aware of the fact that the average annual repair cost for an automobile depends on the age of the automobile. A res

> Investors commonly use the standard deviation of the monthly percentage return for a mutual fund as a measure of the risk for the fund; in such cases, a fund that has a larger standard deviation is considered more risky than a fund with a lower standard

> Consider the following hypothesis test. H0: σ21 = σ22 Ha: σ21 ≠ σ22 a. What is your conclusion if n1 = 21, s21= 8.2, n2 = 26, and s22 = 4.0? Use α = .05 and the p-value approach. b. Repeat the test using the critical value approach.