Question: In order to examine the relationship between

> Consider the following competing hypotheses: The sample consists of 25 observations and the sample correlation coefficient is 0.15. a. Calculate the value of the test statistic and the p-value. b. At the 5% significance level, what is the conclusion

> A social scientist would like to analyze the relationship between educational attainment (in years of higher education) and annual salary (in $1,000s). He collects data on 20 individuals. A portion of the data is as follows: Salary ………………………………………………………

> Osteoporosis is a degenerative disease that primarily affects women over the age of 60. A research analyst wants to forecast sales of Strong Bones, a prescription drug for treating this debilitating disease. She uses the model Sales = β0 + &I

> A sociologist believes that the crime rate in an area is significantly influenced by the area’s poverty rate and median income. Specifically, she hypothesizes crime will increase with poverty and decrease with income. She collects data

> Using data from 50 workers, a researcher estimates Wage = β0 + β1Education + β2Experience + β3Age + ε, where Wage is the hourly wage rate and Education, Experience, and Age are the years of hig

> A marketing firm is considering making up to three new hires. Given its specific needs, the management feels that there is a 60% chance of hiring at least two candidates. There is only a 5% chance that it will not make any hires and a 10% chance that it

> On the first day of class, an economics professor administers a test to gauge the math preparedness of her students. She believes that the performance on this math test and the number of hours studied per week on the course are the primary factors that p

> The owner of several used-car dealerships believes that the selling price of a used car can best be predicted using the car’s age. He uses data on the recent selling price (in $) and age of 20 used sedans to estimate Price = Î&sup

> If a firm spends more on advertising, is it likely to increase sales? Data on annual sales (in $100,000s) and advertising expenditures (in $10,000s) were collected for 20 firms in order to estimate the model Sales = β0 + β1Adverti

> Forty observations were used to estimate y = β0 + β1x1 + β2x2 + ε. A portion of the regression results is shown in the accompanying table. a. What is the estimate for β1? Interpret this value

> Thirty observations were used to estimate y = β0 + β1x1 + β2x2 + ε. A portion of the regression results is shown in the accompanying table. a. What is the estimate for β1? Interpret this valu

> Twenty-four observations were used to estimate y = β0 + β1x + ε. A portion of the regression results is shown in the accompanying table. a. What is the estimate for β1? Interpret this value. b. What is

> The following table lists the National Basketball Association’s leading scorers, their average points per game (PPG), and their average minutes per game (MPG) for 2008. a. Calculate and interpret the sample correlation coefficient be

> Many attempts have been made to relate happiness with various factors. One such study relates happiness with age and finds that holding everything else constant, people are least happy when they are in their mid-40s (The Economist, December 16, 2010). Th

> In 2003, The World Wealth Report first started publishing market shares of global millionaires (The Wall Street Journal, June 25, 2008). At this time, the distribution of the world’s people worth $1 million or more was as follows Region …………………………………………

> Despite Zimbabwe’s shattered economy, with endemic poverty and widespread political strife and repression, thousands of people from overseas still head there every year (BBC News, August 27, 2008). Main attractions include the magnificent Victoria Falls,

> Powerball is a jackpot game with a grand prize starting at $20 million and often rolling over into the hundreds of millions. In 2006, the jackpot was $365 million. The winner may choose to receive the jackpot prize paid over 29 years or as a lump-sum pay

> Go to www.zillow.com/ and find the sale price data of 20 single-family homes sold in Las Vegas, Nevada, in the last 30 days. In the data set, include the sale price, the number of bedrooms, the square footage, and the age of the house. What type of data

> A rent-to-own (RTO) agreement appeals to low-income and financially distressed consumers. It allows immediate access to merchandise, and by making all payments, the consumer acquires the merchandise. At the same time, goods can be returned at any point w

> A study conducted in September and October of 2010 found that fewer than half of employers who hired new college graduates last academic year plan to definitely do so again (The Wall Street Journal, November 29, 2010). Suppose the hiring intentions of th

> The value of a college degree is greater than it has been in nearly half a century, at least when compared to the prospect of not getting a degree Due to this fact, more and more people are obtaining college degrees, despite the soaring costs. The accomp

> Reorder point decisions for a particular part at an automotive parts distributor are based on the assumption that weekly demand is normally distributed. (Note: “Reorder point” is the inventory level at which a replenishment order is placed; it should be

> You suspect that an unscrupulous employee at a casino has tampered with a die; that is, he is using a loaded die. In order to test this claim, you roll the die 200 times and obtain the following frequencies: a. Specify the null and alternative hypothes

> A software company develops and markets a popular business simulation/modeling program. A random number generator contained in the program provides random values from various probability distributions. The software design group would like to validate tha

> The human resources department would like to consolidate the current set of retirement plan options offered to specific employee pay groups into a single plan for all pay groups (salaried, hourly, or piecework). A sample of 585 employees of various pay g

> The operations manager at Electro Tech, an electronics manufacturing company, believes that workers on particular shifts may be more likely to phone in “sick” than those on other shifts. To test this belief, she has co

> Color coding is often used in manufacturing operations to display production status or to identify/prioritize materials. For example, suppose “green” status indicates that an assembly line is operating normally, “yellow” indicates it is down waiting on p

> An automotive parts company has been besieged with poor publicity over the past few years due to several highly publicized product recalls that have tarnished its public image. This has prompted a series of quality improvement initiatives. Currently, the

> The number of homes that a realtor sells over a one-month period has the following probability distribution. Number of Houses Sold ……………………………………………………. Probability 0 ……………………………………………………………………………………………… 0.30 1 ……………………………………………………………………………………………… 0.50

> The data that accompany this exercise show various variables, including price and square footage, for 36 single-family homes in Arlington, Massachusetts, sold in the first quarter of 2009. a. Use the Jarque-Bera test to test if house prices are not norm

> The following frequency distribution shows the monthly stock returns (in percent) for Home Depot for the years 2003 through 2007. Monthly Returns ……………&a

> Given a shaky economy and high heating costs, more and more households are struggling to pay utility bills (The Wall Street Journal, February 14, 2008). Particularly hard hit are households with homes heated with propane or heating oil. Many of these hou

> A poll asked 3,228 Americans aged 16 to 21 whether they are likely to serve in the U.S. military. The following table, cross-classified by a person’s sex and race, reports those who responded that are likely or very likely to serve in t

> An analysis of variance experiment produced a portion of the following ANOVA table. Source of Variation a. Specify the competing hypotheses in order to determine whether some differences exist between the population means. b. Fill in the missing statis

> An analysis of variance experiment produced a portion of the accompanying ANOVA table. a. Specify the competing hypotheses in order to determine whether some differences exist between the population means. b. Fill in the missing statistics in the ANOVA

> Consider the following regression results based on 20 observations. a. Specify the hypotheses to determine if the intercept differs from zero. Perform this test at the 5% significance level. b. Construct the 95% confidence interval for the slope coeffi

> Mechanics In a simple linear regression based on 30 observations, it is found that b1 = 3.25 and se (b1) = 1.36. Consider the hypotheses: a. Calculate the value of the test statistic. b. Find the p-value. c. At the 5% significance level, what is the c

> Random sampling from four normally distributed populations produced the following data: a. Calculate the grand mean. b. Calculate SSTR and MSTR. c. Calculate SSE and MSE. d. Specify the competing hypotheses in order to determine whether some differen

> Mechanics A random sample of five observations from three normally distributed populations produced the following data: a. Calculate the grand mean. b.Calculate SSTR and MSTR. c. Calculate SSE and MSE. d.Specify the competing hypotheses in order to d

> Fifty percent of the customers who go to Sears Auto Center for tires buy four tires and 30% buy two tires. Moreover, 18% buy fewer than two tires, with 5% buying none. a. What is the probability that a customer buys three tires? b. Construct a cumulative

> Akiko Hamaguchi is a manager at a small sushi restaurant in Phoenix, Arizona. Akiko is concerned that the weak economic environment has hampered foot traffic in her area, thus causing a dramatic decline in sales. In order to offset the decline in sales,

> In the carbonated beverage industry, dispensing pressure can be an important factor in achieving accurate fill volumes. Too little pressure can slow down the dispensing process. Too much pressure can create excess “fizzâ€&#15

> Wenton Powersports produces dune buggies. They have three assembly lines, “Razor,” “Blazer,” and “Tracer,” named after the particular dune buggy m

> For a sample of 20 New England cities, a sociologist studies the crime rate in each city (crimes per 100,000 residents) as a function of its poverty rate (in %) and its median income (in $1,000s). A portion of the regression results is shown in the accom

> In a simple linear regression based on 25 observations, it is found that b1 = 0.5 and se(b1) = 0.3. Consider the hypotheses: a. Calculate the value of the test statistic and the p-value. b. At the 5% significance level, what is the conclusion to the t

> A study on the evolution of mankind shows that, with a few exceptions, world-record holders in the 100-meter dash have progressively gotten bigger over time (The Wall Street Journal, July 22, 2009). The following table shows runners who have held the rec

> A survey by Genworth Financial Inc., a financial-services company, concludes that the cost of long-term care in the United States varies significantly, depending on where an individual lives (The Wall Street Journal, May 16, 2009). An economist collects

> A well-known conglomerate claims that its detergent “whitens and brightens better than all the rest.” In order to compare the cleansing action of the top three brands of detergents, 24 swatches of white cloth were soi

> Applications Asian residents in Boston have the highest average life expectancy of any racial or ethnic group—a decade longer than black residents (The Boston Globe, August 16, 2010). Suppose sample results indicative of the overall res

> A machine that is programmed to package 1.20 pounds of cereal is being tested for its accuracy. In a sample of 36 cereal boxes, the sample mean filling weight is calculated as 1.22 pounds. The population standard deviation is known to be 0.06 pound. a. I

> Applications A marketing manager analyzes the relationship between the annual sales of a firm (in $100,000s) and its advertising expenditures (in $10,000s). He collects data from 20 firms and estimates Sales = β0 + β1Advertising +

> The following ANOVA table was obtained when estimating a multiple linear regression model. a. How many explanatory variables were specified in the model? How many observations were used? b. Specify the hypotheses to determine whether the explanatory v

> A researcher examines the factors that influence student performance. She gathers data on 224 school districts in Massachusetts. The response variable is the students’ mean score on a standardized test (Score). She uses four explanatory

> Consider a regression model for per capita income, y. The explanatory variables consist of the percentage of the population in the U.S. that is (a) without a high school diploma, x1, (b) foreign born, x2, and (c) non-English speaking, x3. A portion of th

> A nutritionist wants to understand the influence of income and healthy food on the incidence of smoking. He collects 2009 data on the percentage of smokers in each state in the U.S. and the corresponding median income (in $) and the percentage of the pop

> A research analyst is trying to determine whether a firm’s priceearnings (P⁄E) and price-sales (P⁄S) ratios can explain the firm’s stock performance over the past year. Generally, a

> A government researcher examines the factors that influence a city’s crime rate. For 41 cities, she collects the crime rate (crimes per 100,000 residents), the poverty rate (in %), the median income (in $1,000s), the percent of resident

> George believes that the returns of mutual funds are influenced by annual turnover rates and annual expense ratios. In order to substantiate his claim, he randomly selects 20 mutual funds and collects data on each fund’s five-year annua

> A researcher studies the relationship between SAT scores, the test-taker’s family income (Income), and his/her grade point average (GPA). Data are collected from 24 students. A portion of the data is shown in the accompanying table. a

> The home ownership rate in the U.S. was 67.4% in 2009. In order to determine if home ownership is linked with income, 2009 state-level data on the home ownership rate (Ownership in %) and median household income (Income in $) were collected. A portion of

> A sample of the salaries of assistant professors on the business faculty at a local university revealed a mean income of $72,000 with a standard deviation of $3,000. a. Using Chebyshev’s theorem, what percentage of the faculty earns at least $66,000 but

> When estimating a multiple linear regression model based on 30 observations, the following results were obtained. // a. Specify the hypotheses to determine whether x1 is linearly related to y. At the 5% significance level, are x1 and y linearly related

> A sociologist wishes to study the relationship between happiness and age. He interviews 24 individuals and collects data on age and happiness, measured on a scale from 0 to 100. Estimate: Happiness = β0 + β1Age + ε. At the 1% significance level, is Age s

> The labor estimation group at Sturdy Electronics, a contract electronics manufacturer of printed circuit boards, wants to simplify the process it uses to quote production costs to potential customers. They have identified the primary drivers for producti

> The consumption function is one of the key relationships in economics, where consumption y depends on disposable income x. Consider the quarterly data for these seasonally adjusted variables, measured in billions of dollars. A portion of the data is show

> Healthy living has always been an important goal for any society. In an ad campaign for Walt Disney, former First Lady Michelle Obama shows parents and children that eating well and exercising can also be fun (USA Today, September 30, 2010). Consider a r

> Consider the monthly rent (Rent in $) of a home in Ann Arbor, Michigan, as a function of the number of bedrooms (Beds), the number of bathrooms (Baths), and square footage (Sqft). a. Estimate: Rent = β0 + β1Beds + β2Baths + β3Sqft + ε. b. Which of the e

> Consider the following regression results based on 40 observations. a. Specify the hypotheses to determine if the slope differs from minus one. b. Calculate the value of the test statistic and the p-value. c. At the 5% significance level, does the s

> Quick2U, a delivery company, would like to standardize its delivery charge model for shipments (Charge in $) such that customers will better understand their delivery costs. Three explanatory variables are used: (1) distance (in miles), (2) shipment weig

> A simple linear regression, y = β0 + β1x + ε, is estimated with time series data. The resulting residuals e and the time variable t are shown in the accompanying table. a. Graph the residuals against time and look f

> A simple linear regression, y = β0 + β1x + ε, is estimated with cross-sectional data. The resulting residuals e along with the values of the explanatory variable x are shown in the accompanying table. a. Graph the r

> Consider a sample with 10 observations of −3, 8, 4, 2, −4, 15, 6, 0, −4, and 5. Use z-scores to determine if there are any outliers in the data; assume a bell-shaped distribution.

> Using 20 observations, the multiple regression model y = β0 + β1x1 + β2x2 + ε was estimated. A portion of the regression results is as follows: a. At the 5% significance level, are the explanatory variab

> The maintenance manager at a trucking company wants to build a regression model to forecast the time until the first engine overhaul (Time in years) based on four explanatory variables: (1) annual miles driven (Miles in 1,000s), (2) average load weight (

> Estimate: Price = β0 + β1Sqft + β2Beds + β2Baths + ε, where Price, Sqft, Beds, and Baths refer to home price, square footage, number of bedrooms, and number of bathrooms, respectively. Construct the 95% confidence interval for the expected price of a 2,5

> Estimate: Debt = β0 + β1Income + ε, where Debt (in $) is the average debt payments for a household in a particular city and Income (in $1,000s) is the city’s median income. a. Construct the 95% confidence interval for expected debt payments if income is

> GPA = β0 + β1GRE + ε, where GRE is a student’s score on the math portion of the Graduate Record Examination (GRE) score and GPA is the student’s grade point average in graduate school. a. Construct the 90% confidence interval for the expected GPA for an

> Estimate: Height = β0 + β1Fertilizer + ε, where Height is a tomato plant’s height (in inches) and Fertilizer is the fertilizer amount (in ounces). a. Calculate and interpret the 90% confidence interval for the mean height of a tomato plant that receives

> FILE Education. Estimate: Salary = β0 + β1Education + ε, where Salary is measured in $1,000s and Education refers to years of higher education. a. Construct the 90% confidence interval for the expected salary for an individual who completed 6 years of h

> Data are drawn from a bell-shaped distribution with a mean of 50 and a standard deviation of 12. There are 250 observations in the data set. Approximately how many observations are more than 74?

> An automotive workers union, in conjunction with top management, is negotiating a new hourly pay policy for union workers based on three variables: (1) job class, (2) years with the company, and (3) years as a union member at any company. The goal is to

> A multiple regression model is used to predict an NFL team’s winning record (Win in %). For the explanatory variables, the average rushing yards (Rush) and the average passing yards (Pass) are used to capture offense, and the average ya

> The manager of a local Costo store is in the process of making hiring decisions for selling mobile phone contracts. She believes that the sale of mobile phone contracts depends crucially on the number of hours clocked by male and female employees. She co

> A researcher interviews 50 employees of a large manufacturer and collects data on each worker’s hourly wage (Wage in $), years of higher education (EDUC), experience (EXPER), and age (AGE). A portion of the data is shown in the accompan

> Lisa Fisher is a business school professor who would like to analyze university factors that enhance innovation. She collects data on 143 universities in 2008 for a regression where the response variable is the number of startups (Startups), which is use

> A financial analyst believes that the best way to predict a firm’s returns is by using the firm’s price-to-earnings ratio (P⁄E) and its price-to-sales ratio (P⁄S) as explanatory vari

> Applications A real estate analyst estimates the following regression, relating a house price to its square footage (Sqft): In an attempt to improve the results, he adds two more explanatory variables: the number of bedrooms (Beds) and the number of ba

> Consider a portion of simple linear regression results, In an attempt to improve the results, two explanatory variables are added. The relevant regression results are the following: a. Formulate the hypotheses to determine whether x2 and x3 are joint

> Consider the multiple linear regression model, y = β0 + β1x1 + β2x2 + ε. Define the restricted and unrestricted models if the hypotheses are Hoi Bi + Bz = 1 and Ha: Bi + B2 # 1.

> A data set has a mean of 80 and a standard deviation of 5. a. Using Chebyshev’s theorem, what percentage of the observations fall between 70 and 90? b. Using Chebyshev’s theorem, what percentage of the observations fall between 65 and 95?

> Consider the multiple linear regression model, y = β0 + β1x1 + β2x2 + β3x3 + ε. You wish to test whether the slope coefficients β1 and β3 are statistically different from each other. Define the restricted and unrestricted models needed to conduct the tes

> On the first day of class, an economics professor administers a test to gauge the math preparedness of her students. She believes that the performance on this math test and the number of hours studied per week on the course are the primary factors that p

> A realtor examines the factors that influence the price of a house in Arlington, Massachusetts. He collects data on recent house sales (Price) and notes each house’s square footage (Sqft) as well as its number of bedrooms (Beds) and num

> Caterpillar, Inc. manufactures and sells heavy construction equipment worldwide. The performance of Caterpillar’s stock is likely to be strongly influenced by the economy. For instance, during the subprime mortgage crisis, the value of

> The facility manager at a pharmaceutical company wants to build a regression model to forecast monthly electricity cost. Three main variables are thought to dictate electricity cost: (1) average outdoor temperature (Temp in °F), (2) working days per mont

> The maintenance manager at a trucking company wants to build a regression model to forecast the time until the first engine overhaul (Time in years) based on four explanatory variables: (1) annual miles driven (Miles in 1,000s), (2) average load weight (

> The cutting department at Best Cuts, a furniture manufacturer, is examining the effect of depth of cut and feed rate on the surface roughness of table legs used in a popular dining room table model. The accompanying table shows the surface roughness resu

> A production manager is investigating whether the operator training method (factor A) will affect the resulting output for a particular product. Three training methods were studied: a full-day workshop (most intensive), in-line training, and as-needed tr

> A management consultant wants to determine whether the age and gender of a restaurant’s wait staff influence the size of the tip the customer leaves. Three age brackets (factor A in columns: young, middle-age, older) and gender (factor

> An environmentalist wants to examine whether average fuel consumption (measured in miles per gallon) is affected by fuel type (factor A) and type of hybrid (factor B). A two-way ANOVA experiment with interaction is performed. The results are shown in the