Question: The product manager at a subsidiary of

> In Exercise 44, the company Zappos was omitted. Here is a scatterplot of the data with Zappos plotted as an x: a) In words, what does the outlying point say about Zappos? b) What effect would this point have on the regression, had it been left with t

> In Exercise 43, we examined the Worldwide Cost of Living Survey cost of living index. Now we use the Restaurant Price Index to predict total cost of living. Here are the results: a) How do you interpret the coefficient of Restaurant price? b) The R2 o

> Fortune Magazine publishes the top 100 companies to work for every year. Among the information listed is the percentage growth in jobs at each company. The output below shows the regression of job growth (%) in the current year on job growth from two yea

> The Worldwide Cost of Living Survey published by Numbeo.com provides an index that expresses the cost of living in other cities as a percentage of the New York cost. For example, in 2017, the cost of living index in Geneva was 142, which means that it wa

> There are 168 hours in a week. If you spend all of it sleeping and having fun, you will earn very little money. On the other hand, if you spend much of it working, do you earn more? In other words, do people earn more money each year when they work a gre

> In 2014, cnet.com listed the battery life (in hours) and maximum luminous intensity (i.e., screen brightness, in cd>m2) for a sample of tablet computers. We want to know if we can predict battery life from the maximum brightness. (reviews.cnet.com/830

> Using a statistics program, consider again the relationship between the sales and profits of Fortune 500 companies that you analyzed in Exercise 38. a) Find a 95% confidence interval for the slope of the regression line. Interpret your interval in conte

> Using a statistics program, consider again the relationship between the population and ozone level of U.S. cities that you analyzed in Exercise 37. a) Give a 90% confidence interval for the approximate increase in ozone level associated with each additi

> A business analyst was interested in the relationship between a company’s sales and its profits. She collected data (in millions of dollars) from a random sample of Fortune 500 companies and created the regression analysis and summary s

> A market researcher for a provider of iPhone accessories wants to know the proportion of customers who own cars to assess the market for a new iPhone dashboard mount. A survey of 500 customers indicates that 76% own cars. a) What is the standard deviati

> The Environmental Protection Agency is examining the relationship between the ozone level (in parts per million) and the population (in millions) of U.S. cities. Part of the regression analysis is shown. a) We suspect that the greater the population o

> Consider the high school SAT scores data from Exercise 31. a) Find a 90% confidence interval for the slope of the true line describing the association between Math and Verbal scores. b) Explain in this context what your confidence interval means.

> Consider again the data in Exercise 29 about the gas mileage and weights of cars. a) Create a 95% confidence interval for the slope of the regression line. b) Explain in this context what your confidence interval means.

> The Gallup organization has, over six decades, periodically asked the following question: If your party nominated a generally well-qualified person for president who happened to be a woman, would you vote for that person? We wonder if the proportion of t

> Football owners are constantly in competition for good players. The more wins, the more likely that the team will provide good business returns for the owners. The resources that each of the 32 teams has in the National Football League (NFL) vary, but th

> How strong is the association between labor productivity and labor costs? Data from the Bureau of Labor Statistics for labor productivity, as measured by Output per Employee, and Unit Labor Costs across industries, are used to examine this relationship (

> How strong was the association between student scores on the Math and Verbal sections of the old SAT? Scores on this exam ranged from 200 to 800 and were widely used by college admissions offices. Here are summary statistics, regression analysis, and plo

> Consumer Reports listed the price (in dollars) and power (in cold cranking amps) of auto batteries. We want to know if more expensive batteries are generally better in terms of starting power. Here are the regression and residual output, where the respon

> A consumer organization has reported test data for 50 car models. We will examine the association between the weight of the car (in thousands of pounds) and the fuel efficiency (in miles per gallon). Use the data provided on the disk to answer the follow

> A business analyst is looking at a company’s assets and sales to determine the relationship (if any) between the two measures. She has data (in $million) from a random sample of 79 Fortune 500 companies, and obtained the linear regressi

> A marketing researcher for a phone company surveys 100 people and finds that that proportion of clients who are likely to switch providers when their contract expires is 0.15. a) What is the standard deviation of the sampling distribution of the proport

> Based on the analysis of used car prices you did for Exercise 25, if appropriate, create a 95% confidence interval for the slope of the regression line and explain what your interval means in context.

> The following software results provide information about the size (in square feet) of 18 homes in Ithaca, New York, and the city’s assessed value of those homes, where the response variable is Assessment. a) Explain why inference for

> Classified ads in a newspaper offered several used Toyota Corollas for sale. Listed below are the ages of the cars and the advertised prices. a) Make a scatterplot for these data. b) Do you think a linear model is appropriate? Explain. c) Find the e

> Using unemployment data provided by the World Bank, investigate the association between the male unemployment rate in 2014 and 2017. a) Find a regression model predicting the 2017 rate from the 2014 rate. b) Examine the residuals to determine if a line

> The index of deflated turnover for retail trade shows the activity in volume of the retail trade sector. The United Nations Statistics Division reports Retail trade deflated sales/turnover (seasonally adjusted) with 2005 = 100. The data file holds this i

> The Brief Case for Chapter 4 listed the rate of return for 98 mutual funds over the previous 3-year and 5-year periods. It’s common for advertisements to carry the disclaimer that “past returns may not be indicative of future performance.” Do these data

> In an investigation of environmental causes of disease, data were collected on the annual mortality rate (deaths per 100,000) for males in 61 large towns in England and Wales. In addition, the water hardness was recorded as the calcium concentration (par

> Exercise 18 shows computer output examining the association between the sizes of houses and their sale prices. a) Check the assumptions and conditions for inference. b) Find a 95% confidence interval for the slope and interpret it.

> Exercise 17 shows computer output examining the association between the length of a movie and its cost. a) Check the assumptions and conditions for inference. b) Find a 95% confidence interval for the slope and interpret it.

> How does the price of a house depend on its size? Data from Saratoga, New York, on 1057 randomly selected houses that had been sold include data on price ($) and Living Area (ft2), producing the following graphs and computer output: a) Explain in words

> A tourist agency wants to know what proportion of visitors to the Eiffel Tower are from the Far East. To find out they survey 100 people in the line to purchase tickets to the top of the tower one Sunday afternoon in May. Are all the assumptions and cond

> How does the cost of a movie depend on its length? Data on the cost (millions of dollars) and the running time (minutes) for major release films in one recent year are summarized in these plots and computer output: a) Explain in words and numbers wh

> The earth has been getting warmer. Most climate scientists agree that one important cause of the warming is the increase in atmospheric levels of carbon dioxide (CO2), a greenhouse gas. Here is part of a regression analysis of the mean annual air tempera

> Several studies have found that the frequency with which shoppers browse Internet retailers is related to the frequency with which they actually purchase products and/or services online. Here are data showing the age of respondents and their answer to th

> For each of the following situations, state whether you’d use a chi-square goodness-of-fit test, a chi-square test of homogeneity, a chi-square test of independence, or some other statistical test. a) Is the quality of a car affected by what day it was

> For each of the following situations, state whether you’d use a chi-square goodness-of-fit test, chi square test of homogeneity, chi-square test of independence, or some other statistical test. a) A brokerage firm wants to see whether the type of accoun

> A marketing executive tested two incentives to see what percentage of customers would enroll in a new Web-based loyalty program. The customers were asked to log on to their accounts on the Web and provide some demographic and spending information. As an

> In 2010, the U.S. Congress passed the historic health care reform bill that will provide some type of coverage for the millions of Americans without health care insurance. Just how widespread is the lack of medical coverage in 2016, years after health ca

> You are on the financial planning team for monitoring a high spending segment of a credit card. You know that customers tend to spend more during December before the holidays, but you’re not sure about the pattern of spending in the months after the holi

> In Chapter 4, we examined the regression of the sales price of a home on its size and saw that larger homes generally fetch a higher price. How much can we learn about a house from the fact that it has a fireplace or more than the average number of bedro

> A philanthropic organization collects and buys data on their donor base. The full database contains about 4.5 million donors and over 400 variables collected (continued) on each, but the dataset Donor profiles is a sample of 916 donors and includes the v

> A real estate agent wants to know how many owners of homes worth over $1,000,000 might be considering putting their home on the market in the next 12 months. He surveys 40 of them and finds that 10 of them are considering such a move. Are all the assumpt

> Using the Paralyzed Veterans dataset, construct a 95% confidence interval for the mean age of a potential donor to the Paralyzed Veterans. Test the hypothesis that the mean age is 62 years old. Discuss what the confidence interval says about the hypothes

> In the last chapter, you looked at the data file Real estate sample 1200, which holds the following variables: • Sale Price (in $) • Lot size (size of the lot in acres) • Waterfront (Yes, No) • Age (in years) • Central Air (Yes, No) • Fuel Type (Wood, Oi

> A real estate agent is trying to understand the pricing of homes in her area, a region comprised of small to midsize towns and a small city. For each of 1200 homes recently sold in the region, the file Real estate sample 1200 holds the following variable

> Utilities must forecast the demand for energy use far into the future because it takes decades to plan and build new power plants. Ron Baker, who worked for New York State Electric and Gas (NYSEG), had the job of predicting the proportion of homes that w

> In 2011, when the Gallup organization polled investors, 34% rated gold the best long-term investment. But in April of 2017 Gallup surveyed a random sample of U.S. adults (news.gallup.com/poll/208820/americans-favor-real-estate-long-terminvestment.aspx).

> Every spring, Nenana, Alaska, hosts a contest in which participants try to guess the exact minute that a wooden tripod placed on the frozen Tanana River will fall through the breaking ice. The contest started in 1917 as a diversion for railroad engineers

> In Exercise 59, we looked at the times in two different heats for the 800-m men’s run from the 2012 Olympics. Unlike track events, swimming heats are not determined at random. Instead, swimmers are seeded so that better swimmers are pla

> In Olympic running events, preliminary heats are determined by random draw, so we should expect the ability level of runners in the various heats to be about the same, on average. The table gives the times (in seconds) for the 800-m menâ€&#153

> Here’s some additional information about the pizza sales data presented in Exercise 57. It is generally thought that sales spike during the weeks leading up to AFC and NFC football championship games, as well as leading up to the Super

> The proportion of adult women in the United States is approximately 51%. A marketing survey telephones 400 people at random. a) What is the sampling distribution of the observed proportion that are women? b) What is the standard deviation of that propo

> A national food product company believes that it sells more frozen pizza during the winter months than during the summer months. Average weekly sales for a sample of stores in the Baltimore area over a three-year period provided the following data for sa

> The average credit card debt carried by college students was compared at public versus private universities. It was reported that a significant difference existed between the two types of institutions and that students at private universities carried hig

> The National Assessment in Education Program compared science scores for students who had home Internet access with the scores of those who did not, as shown in the graph. They report that the differences are statistically significant. a) Explain what

> The U.S. Bureau of Economic Analysis provides information on the GDP in the United States by metropolitan area (www.bea.gov). The Bureau recently released figures that showed the percent change in real GDP by metropolitan area for 2004–

> The U.S. Bureau of Economic Analysis also provides information on the growth of the U.S. economy (www.bea.gov). The Bureau recently released figures that they claimed showed a growth spurt in the western region of the United States. Using the table and m

> The U.S. Bureau of Economic Analysis provides information on the Gross Domestic Product Per Capita (GDP PC) in the United States by state (www.bea.gov). The Bureau recently released figures that showed the real (GDP PC) by state for 2016. Using the data

> In a recent study of enterprise resource planning (ERP) system effectiveness, researchers asked companies about how they assessed the success of their ERP systems. Out of 335 manufacturing companies surveyed, they found that 201 used return on investment

> It has become more common for shoppers to “comparison shop” using the Internet. Respondents to a Pew survey in 2013 who owned cell phones were asked whether they had, in the past 30 days, looked up the price of a produ

> The Pew Internet & American Life Project routinely conducts surveys to gauge the impact of the Internet and technology on daily life. A recent survey asked respondents if they read online journals or blogs, an Internet activity of potential interest

> Every year, Fortune magazine lists the 100 best companies to work for, based on criteria such as pay, benefits, days off, and diversity. In 2018, the top three were Sales Force, Wegmans Food Markets, and Ultimate Softeware. In 2017, of the top 30, 10 wer

> The investment website of Exercise 1 draws a random sample of 200 investors from their customers. Suppose that the true proportion of smartphone users is 36%. a) What would the standard deviation of the sampling distribution of the proportion of smartph

> Use the survey results in the table below to investigate differences in employee job satisfaction among organizations in the United States with different management styles. a) Select the appropriate procedure. b) Check the assumptions. c) State the hyp

> Consider only the companies that have outsourced their IT and HR business segments. Do these data suggest significant differences between companies in the financial and industrial goods sectors with regard to their outsourcing decisions? a) Select the

> Many companies have chosen to outsource segments of their business to external providers in order to cut costs and improve quality and/ or efficiencies. Common business segments that are outsourced include Information Technology (IT) and Human Resources

> Find a 95% confidence interval for the difference in the proportion of women who survived and the proportion of men who survived for the data in Exercise 44. (Assume the passengers on the Titanic were representative of others who might have taken the tri

> Find a 95% confidence interval for the difference in the proportions of Black renters in the two sections for the data in Exercise 43.

> Newspaper headlines at the time and traditional wisdom in the succeeding decades have held that women and children escaped the Titanic in greater proportion than men. Here’s a table with the relevant data. Do you think that survival was

> The director of a small business development center located in a mid-sized city is reviewing data about its clients. In particular, she is interested in examining if the distribution of business owners across the various stages of the business life cycle

> In some situations where the expected counts are too small, as in Exercise 36, we can complete an analysis anyway. We can often proceed after combining cells in some way that makes sense and also produces a table in which the conditions are satisfied. He

> A recent report concludes that while Internet users like the convenience of online shopping, they do have concerns about privacy and security (Online Shopping, Washington, DC, Pew Internet & American Life Project, February 2008). A random sample of a

> The proportion of adult women in the United States is approximately 51%. A marketing survey telephones 400 people at random. a) What proportion of women in the sample of 400 would you expect to see? b) How many women, on average, would you expect to fi

> The Cornell National Social Survey8 asked 1000 U.S. adults about their employment status and whether they owned stocks. This table gives the counts of the 938 respondents: Is there a relationship between employment status and stock ownership? a) Select

> A leading CEO mentoring organization offers a program for chief executives, presidents, and business owners with a focus on developing entrepreneurial skills. Women and men executives that recently completed the program rated its value. Are perceptions o

> Pew Research surveyed U.S. adults in December 2011. They asked how important it is “to you personally” to be successful in a high-paying career or profession. Among 18- to 34-year-old respondents, do men and women have

> A full service brokerage firm surveyed a random sample of 1200 clients asking them to indicate the likelihood that they would add inflation-linked annuities and bonds to their portfolios within the next year. The table below shows the distribution of res

> A large company in the northeastern United States that buys fish from local fishermen and distributes them to major companies and restaurants is considering launching a new ad campaign on the health benefits of fish. As evidence, they would like to cite

> Immigration reform has focused on dividing illegal immigrants into two groups: long-term and short-term. In a random sample of 958 construction workers from the Northeast, 66 are illegal short-term immigrants. In the Midwest, 42 out of a sample of 1070 a

> In early 2012, the proportion of mortgages that were “under water”—a negative equity position in which the homeowner owes more than the value of the home—was highest in Nevada and Arizona (s.wsj .net/public/resources/documents/info-NEGATIVE_ EQUITY_0911.

> Public libraries are not run for profit, but they must know their customers. A Pew Research survey in November 2012 found that 426 of 584 surveyed parents of young children had current library cards. 967 of 1668 adults without young children had library

> GfK Roper Consulting gathers information on consumer preferences around the world to help companies monitor attitudes about health, food, and health care products. They asked people in many different cultures how they felt about the following statement:

> A recent report suggests that Chief Information Officers (CIOs) who report directly to Chief Financial Officers (CFOs) rather than Chief Executive Officers (CEOs) are more likely to have IT agendas that deal with cost cutting and compliance (SearchCIO.co

> As in Exercise 17, you want to estimate the proportion of traditional college students on your campus who own their own car. However, from some research on other college campuses, you believe the proportion will be near 20%. a) What sample size is neede

> For the regression of Exercise 1, find the standard error of the regression slope. Show all three values that go into the calculation. Exercise 1: A website that rents movies online recorded the age and the number of movies rented during the past month

> A survey of 430 randomly chosen adults finds that 47 of 222 men and 37 of 208 women had purchased books online. a) Is there evidence that the sex of the person and whether they buy books online are associated? b) If your conclusion in fact proves to be

> In March and April of 2011, the Pew Research Center asked 2142 U.S. adults and 1055 college presidents whether they would “rate the job the higher education system is doing in providing value for the money spent by students and their fa

> It’s common folk wisdom that cranberries can help prevent urinary tract infections in women. A leading producer of cranberry juice would like to use this information in their next ad campaign, so they need evidence of this claim. In 2001, the British Med

> Consumer Reports uses surveys given to subscribers of its magazine and website (www.ConsumerReports.org) to measure reliability in automobiles. This annual survey asks about problems that consumers have had with their cars, vans, SUVs, or trucks during t

> Students in an Introductory statistics class at a large university were classified by birth order and by the college they attend. a) What kind of chi-square test is appropriate—goodnessof- fit, homogeneity, or independence? b) State y

> The table shows the rank attained by male and female officers in the New York City Police Department (NYPD). Do these data indicate that men and women are equitably represented at all levels of the department? (All possible ranks in the NYPD are shown.)

> Here is a table showing who survived the sinking of the Titanic based on whether they were crew members or passengers booked in first-, second-, or third-class staterooms. a) If we draw an individual at random from this table, what’s

> Census data for New York City indicate that 29.2% of the under-18 population is white, 28.2% black, 31.5% Latino, 9.1% Asian, and 2% are of other ethnicities. The New York Civil Liberties Union points out that of 26,181 police officers, 64.8% are white,

> For a lottery to be successful, the public must have confidence in its fairness. One of the lotteries in Maryland is Pick-3 Lottery, where 3 random digits are drawn each day.7 A fair game depends on every value (0 to 9) being equally likely at each of th

> A sales representative who is on the road visiting clients thinks that, on average, he drives the same distance each day of the week. He keeps track of his mileage for several weeks and discovers that he averages 122 miles on Mondays, 203 miles on Tuesda

> Suppose you want to estimate the proportion of traditional college students on your campus who own their own car. You have no preconceived idea of what that proportion might be. a) What sample size is needed if you wish to be 95% confident that your esti

> A company advertises that its premium mixture of nuts contains 10% Brazil nuts, 20% cashews, 20% almonds, 10% hazelnuts, and that the rest are peanuts. You buy a large can and separate the various kinds of nuts. Upon weighing them, you find there are 112

> According to recent research (www .nas.org) married couples who met their spouse through an online dating service may have a different divorce rate than those who met “off line.” (“Online Mating” from Proceedings of the National Academy of Sciences of th

> After getting trounced by your little brother in a children’s game, you suspect that the die he gave you is unfair. To check, you roll it 60 times, recording the number of times each face appears. Do these results cast doubt on the die&