Question: A human resource specialist wants to determine

> A data analyst for an online store wonders whether average customer visits to the store’s website vary by day of the week. He collects daily unique visits to the website for a 12-week period; a portion of the data is shown in the accomp

> An accounting professor wants to know if students perform the same on the departmental final exam irrespective of the accounting section they attend. She randomly selects the exam scores of 20 students from three sections. A portion of the output from co

> The marketing department for an upscale retail catalog company wants to determine if there are differences in the mean customer purchase amounts across the available purchase sources (Internet, phone, or mail-in). Accordingly, samples were taken for 20 r

> Before the Great Recession, job-creating cities in the Sunbelt, like Las Vegas, Phoenix, and Orlando saw their populations, income levels, and housing prices surge. Las Vegas, however, offered something that often eluded these other cities: upward mobili

> An economist wants to determine whether average price/earnings (P/E) ratios differ for firms in three industries. Independent samples of five firms in each industry show the following results: a. At the 5% significance level, determine whether average

> The following table shows the annual returns (in %) for the Fidelity Latin America Fund and the Fidelity Canada Fund from 2005 through 2009. a. Which fund had the higher average return? b. Which fund was riskier over this time period? c. Given a risk

> An employee of a small software company in Minneapolis bikes to work during the summer months. He can travel to work using one of three routes and wonders whether the average commute times (in minutes) differ between the three routes. He obtains the foll

> The marketing manager at Turfco, a lawn mower company, believes that monthly sales across all outlets (stores, online, etc.) are influenced by three key variables: (1) outdoor temperature (in °F), (2) advertising expenditures (in $1,000s), and

> Compressive strength of concrete is affected by several factors, including composition (sand, cement, etc.), mixer type (batch vs. continuous), and curing procedure. Accordingly, a concrete company is conducting an experiment to determine how mixing tech

> Finger dexterity, the ability to make precisely coordinated finger movements to grasp or assemble very small objects, is important in jewelry making. Thus, the manufacturing manager at Gemco, a manufacturer of high-quality watches, wants to develop a reg

> The Marketing Manager at Foodco, a large grocery store, wants to determine if store display location influences sales of a particular grocery item. He instructs employees to rotate the display location of that item every week and then tallies the weekly

> A government agency wants to determine whether the average salaries of four kinds of transportation operators differ. A random sample of five employees in each of the four categories yields the salary data (in $1,000s) given in the accompanying table.

> It is generally believed that a practical major such as business or engineering can really pay off for college graduates (CNNMoney.com, July 22, 2010). Other studies have shown that it is not just the major but also how students perform, as measured by t

> A human resource specialist wants to determine whether the average job satisfaction score (on a scale of 0 to 100) is the same for three different industries and three types of work experience. A randomized block experiment with interaction is performed.

> A consumer advocate examines whether the longevity of car batteries (measured in years) is affected by the brand name (factor A) and whether or not the car is kept in a garage (factor B). Interaction is suspected. The results are shown in the accompanyin

> The marketing group at Buy4Less, a local retail chain, is examining the effect of advertising at various times of day and on various local television channels. Based on 12-week cycles (4 time periods x 3 local channels), three observations (cycles) of we

> Fidelity_Select. The accompanying data file shows the annual return (in percent) for the Fidelity Select Technology Fund and the Fidelity Select Energy Fund from 2000 through 2016. Assume that the return data are bell-shaped. a. Use z-scores to determin

> Ask 20 of your friends whether they live in a dormitory, a rental unit, or other form of accommodation. Also find out their approximate monthly lodging expenses. Create a table that uses this information. What type of data do these numbers represent? Com

> The effects of detergent brand name (factor A) and the temperature of the water (factor B) on the brightness of washed fabrics are being studied. Four brand names and two temperature levels are used; six observations for each combination are examined. Th

> Applications The engineering department at a steel mill is studying the tensile strength of a particular grade of steel when fabricated at various pressures (Factor A) and temperatures (Factor B). The accompanying ANOVA table shows a portion of the resul

> A researcher conducts a two-way ANOVA test with interaction and provides the following ANOVA table. a. Find the missing values in the ANOVA table. b. At the 5% significance level, can you conclude that there is an interaction effect? c. At the 5% sign

> A researcher conducts a two-way ANOVA test with interaction and provides the following ANOVA table. a. At the 1% significance level, can you conclude that there is interaction between the two factors? b. Are you able to conduct tests based on the main

> A two-way analysis of variance experiment with interaction was conducted. Factor A had three levels (columns), factor B had five levels (rows), and six observations were obtained for each combination. The results include the following sum of squares term

> A two-way analysis of variance experiment with interaction was conducted. Factor A had four levels (columns), factor B had three levels (rows), and five observations were obtained for each combination. The results include the following sum of squares ter

> First National Bank employs three real estate appraisers whose job is to establish a property’s market value before the bank offers a mortgage to a prospective buyer. It is imperative that each appraiser values a property with no bias.

> The marketing manager at YumYum, a large deli chain, is testing the effectiveness of four potential advertising strategies. After a two-week trial period for each advertising strategy, sales were evaluated. However, since some store locations have higher

> Given a recent outbreak of illness caused by E. coli bacteria, the mayor in a large city is concerned that some of his restaurant inspectors are not consistent with their evaluations of a restaurant’s cleanliness. In order to investigat

> Metalwork, a supplier of fabricated industrial parts, wants to determine if the average output rate for a particular component is the same across the three work shifts. However, since any of four machines can be used, the machine effect must be controlle

> A survey by AARP (Money, June 2007) reported that approximately 70% of people in the 50 to 64 age bracket have tried some type of alternative therapy (for instance, acupuncture or the use of nutrition supplements). Assume this survey was based on a sampl

> The following output summarizes a portion of the results for a two-way analysis of variance experiment with no interaction. Factor A consists of four different kinds of organic fertilizers, factor B consists of three different kinds of soil acidity level

> During a typical Professional Golf Association (PGA) tournament, the competing golfers play four rounds of golf, where the hole locations are changed for each round. Here are the scores for the top five finishers at the 2009 U.S. Open. The following st

> The following table summarizes a portion of the results for a two-way analysis of variance experiment with no interaction. a. Find the missing values in the ANOVA table. b. At the 5% significance level, can you conclude that the column means differ? c.

> The following table summarizes a portion of the results for a two-way analysis of variance experiment with no interaction. a. Find the missing values in the ANOVA table. b. At the 5% significance level, can you conclude that the column means differ?

> A two-way analysis of variance experiment with no interaction is conducted. Factor A has three levels (columns) and Factor B has five levels (rows). The results include the following sum of squares terms: a. Construct an ANOVA table. b. At the 5% signi

> A two-way analysis of variance experiment with no interaction is conducted. Factor A has four levels (columns) and Factor B has three levels (rows). The results include the following sum of squares terms: a. Construct an ANOVA table. b. At the 1% signi

> The following observations were obtained when conducting a two-way ANOVA experiment with no interaction a. Calculate SST, SSA, SSB, and SSE. b. Calculate MSA, MSB, and MSE. c. Construct an ANOVA table. e. At the 5% significance level, do the levels of

> The following observations were obtained when conducting a two-way ANOVA experiment with no interaction. a. Calculate SST, SSA, SSB, and SSE. b. Calculate MSA, MSB, and MSE. c. Construct an ANOVA table. e. At the 5% significance level, can you concl

> The accompanying table shows a portion of the number of customers that ate at a restaurant on weekend days over the past 52 weeks. a. Verify that the average number of customers that frequent the restaurant differs by weekend day at the 5% significance

> A production manager is examining whether work shift is related to employee absenteeism. The number of days absent over the past year was tallied for random samples of 25 workers on each shift. A portion of the data is shown in the accompanying table.

> On average, an American professional football game lasts about three hours, even though the ball is actually in play only 11 minutes (www.sportsgrid.com, January 14, 2014). Let the standard deviation be 0.4 hour. a. Use Chebyshev’s theorem to approximat

> Producers of a new grass seed called Pearl’s Premium claim that grass grown using its seed blend requires less maintenance as compared to other brands (The Boston Globe, July 4, 2009). For instance, grass grown using Pearlâ€&

> Elastotech, a plastics company, is trying to determine whether four successive daily batches of their Lexan polycarbonate have the same mean hardness value. Four daily samples of polycarbonate were taken, and the resulting hardness values were measured (

> Do energy costs vary dramatically depending on where you live in the United States? Annual energy costs are collected from 25 households in four regions in the United States. Sample means for each region and a portion of the ANOVA table is shown below.

> In an attempt to improve efficiency, Starbucks has implemented “lean” Japanese techniques at many of its 11,000 U.S. stores (The Wall Street Journal, August 4, 2009). By reducing the time baristas (employees) spend on

> The following output summarizes the results for a one-way analysis of variance experiment in which the treatments were three different hybrid cars and the variable measured was the miles per gallon (mpg) obtained while driving the same route. a. At th

> A one-way analysis of variance experiment produced the following ANOVA table. a. Use Fisher’s LSD method to determine which means differ at the 5% level of significance. b. Use Tukey’s HSD method to determine which m

> A one-way analysis of variance experiment produced the following ANOVA table. a. Conduct an ANOVA test at the 5% significance level to determine if some population means differ. b. Calculate 95% confidence interval estimates for μ1 &acir

> The following statistics are calculated by sampling from four normal populations whose variances are equal: a. Use Fisher’s LSD method to determine which population means differ at α = 0.01. b. Use Tukeyâ€&#1

> The following statistics are computed by sampling from three normal populations whose variances are equal: a. Calculate 95% confidence intervals for μ1 − μ2, μ1 − Î&fra

> An investment strategy has an expected return of 8% and a standard deviation of 6%. Assume investment returns are bell-shaped. a. How likely is it to earn a return between 2% and 14%? b. How likely is it to earn a return greater than 14%? c. How likel

> A horticulturist is studying the relationship between tomato plant height and fertilizer amount. Thirty tomato plants grown in similar conditions were subjected to various amounts of fertilizer (in ounces) over a four-month period, and then their heights

> At the 5% significance level, test whether the explanatory variables jointly influence sales. At the 1% significance level, test whether the unemployment rate is negatively related with sales. At the 1% significance level, test whether advertising expend

> According to a report by the government, new home construction fell to an 18-month low in October 2010 (CNNMoney.com, November 17, 2010). Housing starts, or the number of new homes being built, experienced an 11.7% drop in its seasonally adjusted annual

> Apple Inc. has established a unique reputation in the consumer electronics industry with its development of products such as the iPod, the iPhone, and the iPad. As of May 2010, Apple had surpassed Microsoft as the most valuable company in the world (The

> American football is the highest-paying sport on a per-game basis. Given that the quarterback is considered the most important player on the team, he is typically well compensated. A sports statistician examines the factors that influence a quarterback&a

> The manager of an SAT review program wonders whether the ethnic background of a student and the program’s instructor affect the student’s performance on the SAT. Four ethnicities and three instructors are examined. Ten

> In 2007, the United States experienced the biggest jump in food prices in 17 years (The Wall Street Journal, April 1, 2008). A variety of reasons led to this result, including rising demand for meat and dairy products in emerging overseas markets, increa

> Lisa Grattan, a financial analyst for a small investment firm, collects annual stock return data for 10 firms in the energy industry, 13 firms in the retail industry, and 16 firms in the utilities industry. A portion of the data is shown in the accompany

> Matthew Jordon is a research analyst for a large investment firm. He is preparing a report on the stock performance of Nike, Inc. One aspect of his report will contain inferences concerning monthly stock returns. Before making valid inferences, Matthew f

> A University of Utah study examined 7,925 severely obese adults who had gastric bypass surgery and an identical number of people who did not have the surgery (The Boston Globe, August 23, 2007). The study wanted to investigate whether losing weight throu

> The following table shows the annual returns (in %) and summary measures for the Vanguard Energy Fund and the Vanguard Health Care Fund from 2005 through 2009. a. Which fund had the higher average return? b. Which fund was riskier over this time perio

> For decades, people have believed that boys are innately more capable than girls in math. In other words, due to the intrinsic differences in brains, boys are better suited for doing math than girls. Recent research challenges this stereotype, arguing th

> Nicholas Grammas is an investment analyst examining the performance of two mutual funds with Janus Capital Group: the Janus Balanced Fund and the Janus Overseas Fund. The Janus Balanced Fund (JANBX): This “core” fund c

> Due to environmental concerns and the never-ending volatility of gas prices, drivers are becoming more concerned with their cars’ gasoline consumption. Cameron White, a research analyst at a nonprofit organization, shares these concerns

> Paige Thomsen is about to graduate from college at a local university in San Francisco. Her options are to look for a job in San Francisco or go home to Denver and search for work there. Recent data report that average starting salaries for college gradu

> The Speedo LZR Racer Suit is a high-end, body-length swimsuit that was launched on February 13, 2008. When 17 world records fell at the December 2008 European Short Course Championships in Croatia, many believed a modification in the rules surrounding sw

> Chad Perrone is a financial analyst in Boston studying the annual return data for the health and information technology industries. He randomly samples 20 firms in each industry and notes each firm’s annual return. A portion of the data is shown in the a

> A study by Allstate Insurance Co. finds that 82% of teenagers have used cell phones while driving (The Wall Street Journal, May 5, 2010). Suppose a random sample of 100 teen drivers is taken. a. Discuss the sampling distribution of the sample proportion.

> Europeans are increasingly upset at their leaders for making deep budget cuts to many social programs that are becoming too expensive to sustain. For example, the popularity of then-President Nicolas Sarkozy of France plummeted in 2010, giving him an app

> A random sample of size n = 200 is taken from a population with a population proportion p = 0.75. a. Calculate the expected value and the standard error for the sampling distribution of the sample proportion. b. What is the probability that the sample pr

> Suppose at the beginning of 2012 you decide to invest $20,000 in Driehaus’ Emerging Markets Growth mutual fund. The following table shows the returns (in %) for the years 2012– 2016. Year …………………………………………………………………………….. Annual Return 2012 ……………………………………

> Suppose that IQ scores are normally distributed with a mean of 100 and a standard deviation of 16. a. What is the probability that a randomly selected person will have an IQ score of less than 90? b. What is the probability that the average IQ score of f

> Suppose that the miles-per-gallon (mpg) rating of passenger cars is normally distributed with a mean and a standard deviation of 33.8 and 3.5 mpg, respectively. a. What is the probability that a randomly selected passenger car gets more than 35 mpg? b. W

> A doctor is getting sued for malpractice by four of her former patients. It is believed that the amount that each patient will sue her for is normally distributed with a mean of $800,000 and a standard deviation of $250,000. a. What is the probability th

> In an attempt to determine whether a linear relationship exists between the price of a home (x in $1,000s) and the number of days it takes to sell the home (y), a real estate agent collected the following data from recent sales in his city. a. Calculat

> Consider the following sample data: a. Calculate the covariance. b. Calculate and interpret the correlation coefficient 12 18 20 22 25 15 20 25 22 27

> Consider the following sample data: Calculate the covariance. Calculate and interpret the correlation coefficient -2 4 y -2 -3 -8 -9 -10

> The following table lists U.S. revenue (in $ billions) of the major car-rental companies. Car-Rental Company …………………………………………………. Revenue in 2009 Enterprise ………………………………………………………………………………… $10.7 Hertz …………………………………………………. ………………………………………… 4.7 Avis Bud

> The National Sporting Goods Association (NSGA) conducted a survey of the ages of people who purchased athletic footwear in 2009. The ages are summarized in the following percent frequency distribution. Age of Purchaser …………………………………………………………………………………..

> The Boston Security Analysts Society, Inc. (BSAS) is a nonprofit association that serves as a forum for the exchange of ideas for the investment community. Suppose the ages of its members are based on the following frequency distribution. Age ………………………

> A researcher conducts a mileage economy test involving 80 cars. The accompanying frequency distribution summarizes the results concerning miles per gallon (MPG). MPG ……………………………………………………………………………………………… Frequency 15 up to 20 …………………………………………………………………………

> The following table lists the sale price (in $1,000s) and type of 20 recently sold houses in New Jersey. a. Construct a frequency distribution for types of houses sold in New Jersey. Interpret the results. b. Construct a frequency distribution for hous

> A local hospital provided the following frequency distribution summarizing the weights of babies (in pounds) delivered over the month of January. Weight ………………………………………………………………………………… Number of Babies 2 up to 4 ……………………………………………………………………………………………………….

> Fifty cities provided information on vacancy rates (in %) for local apartments in the following frequency distribution. Vacancy ………………………………………………………………………… Rate Frequency 0 up to 3 …………………………………………………………………………………………….. 5 3 up to 6 ………………………………………………………

> The following relative frequency distribution was constructed from a sample of 50. Calculate the sample mean, the sample variance, and the sample standard deviation. Class ………………………………………………………………………… Relative Frequency 0 up to 2 ……………………………………………………………

> The following relative frequency distribution was constructed from a population of 200. Calculate the population mean, the population variance, and the population standard deviation.

> Consider the following frequency distribution. Class ………………………………………………………………………………………. Frequency 50 up to 60 …………………………………………………………………………………………. 10 60 up to 70 ………………………………………………………………………………………….. 15 70 up to 80 …………………………………………………………………………………………… 8 80

> Consider the following frequency distribution. Class ……………………………………………………………………………………………. Frequency 2 up to 4 …………………………………………………….……………………………………………... 20 4 up to 6 ……………………………………………………………………………………………………… 60 6 up to 8 ……………………………………………………………………………………………

> An investor bought common stock of Microsoft Corporation on three occasions at the following prices. Calculate the average price per share at which the investor bought these shares. Date Price Per Share Number of Shares January 2009 19.58 70 July 2

> What is the perfect summer trip? A National Geographic Kids survey (AAA Horizons, April 2007) asked this question to 316 children ages 8 to 14. Their responses are given in the following frequency distribution. Top Vacation …………………………………………………………….. Cho

> The following table shows the 10 highest-paid chief executive officers of the last decade. a. Calculate the mean compensation for the 10 highest-paid chief executive officers. b. Does the mean accurately reflect the center of the data? Explain. Nam

> It is often assumed that IQ scores follow a bell-shaped distribution with a mean of 100 and a standard deviation of 16. a. Approximately what percentage of scores are between 84 and 116? b. Approximately what percentage of scores are less than 68? c. A

> DOW_PEG. The price-to-earnings growth ratio, or PEG ratio, is the market’s valuation of a company relative to its earnings prospects. A PEG ratio of 1 indicates that the stock’s price is in line with growth expectations. A PEG ratio less than 1 suggests

> The historical returns on a portfolio had an average return of 8% and a standard deviation of 12%. Assume that returns on this portfolio follow a bell-shaped distribution. a. Approximately what percentage of returns were greater than 20%? b. Approximate

> The following table lists the National Basketball Association’s (NBA’s) leading scorers, their average minutes per game (MPG), and their average points per game (PPG) for 2008: Construct and interpret a scatterplot o

> A manager of a local retail store analyzes the relationship between Advertising (in $100s) and Sales (in $1,000s) by reviewing the store’s data for the previous six months. Construct a scatterplot and comment on whether or not a relationship exists. Adv

> At a small firm in Boston, seven employees were asked to report their one-way commute time (in minutes) into the city. Their responses were the following. a. How long was the shortest commute? The longest commute? b. Calculate the mean, the median, an

> Consider a sample with six observations of 6, 9, 12, 10, 9, and 8. Compute the z-scores for each sample observation.

> The accompanying data file shows the Fortune 500 rankings of America’s largest corporations for 2010. Next to each corporation are its market capitalization (in $ billions as of March 26, 2010) and its total return (in %) to investors for the year 2009.

> The Wall Street Journal (August 28, 2006) asked its readers: “Ideally, how many days a week, if any, would you work from home?” The following relative frequency distribution summarizes the responses from 3,478 readers. Days Working from Home ……………………………