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Question: Assume that the test scores from a


Assume that the test scores from a college admissions test are normally distributed, with a mean of 450 and a standard deviation of 100.
a. What percentage of the people taking the test score between 400 and 500?
b. Suppose someone receives a score of 630. What percentage of the people taking the test score better? What percentage score worse?
c. If a particular university will not admit anyone scoring below 480, what percentage of the persons taking the test would be acceptable to the university?


> A random sample of 30 colleges from Kiplinger’s list of the best values in private college provided the data shown in the file BestPrivateColleges (Kiplinger website). The variable named Admit Rate (%) shows the percentage of students that applied to the

> The Russell 1000 is a stock market index consisting of the largest U.S. companies. The Dow Jones Industrial Average is based on 30 large companies. The file Russell gives the annual percentage returns for each of these stock indexes for the years 1988 to

> Over the past 40 years, the percentage of homes in the United States with smoke detectors has risen steadily and has plateaued at about 96% as of 2015 (National Fire Protection Association website). With this increase in the use of home smoke detectors,

> Department of transportation’s study on driving speed and miles per gallon for midsize automobiles resulted in the following data:

> The file StockComparison contains monthly adjusted stock prices for technology company Apple, Inc., and consumer-goods company Procter & Gamble (P&G) from 2013–2018. a. Develop a scatter diagram with Apple stock price on the horizontal axis and P&G stock

> Five observations taken for two variables follow. a. Develop a scatter diagram for these data. b. What does the scatter diagram indicate about a relationship between x and y? c. Compute and interpret the sample covariance. d. Compute and interpret the

> Five observations taken for two variables follow. a. Develop a scatter diagram with x on the horizontal axis. b. What does the scatter diagram developed in part (a) indicate about the relationship between the two variables? c. Compute and interpret the

> The Bureau of Transportation Statistics keeps track of all border crossings through ports of entry along the U.S.-Canadian and U.S.-Mexican borders. The data contained in the file BorderCrossings show the most recently published figures for the number of

> Fortune magazine’s list of the world’s most admired companies for 2014 is provided in the data contained in the file AdmiredCompanies (Fortune magazine website). The data in the column labeled “Return” shows the one-year total return (%) for the top rank

> Consumer Reports provides overall customer satisfaction scores for AT&T, Sprint, T-Mobile, and Verizon cell-phone services in major metropolitan areas throughout the United States. The rating for each service reflects the overall customer satisfactio

> Three firms carry inventories that differ in size. Firm A’s inventory contains 2000 items, firm B’s inventory contains 5000 items, and firm C’s inventory contains 10,000 items. The population standard deviation for the cost of the items in each firm’s in

> Annual sales, in millions of dollars, for 21 pharmaceutical companies follow. a. Provide a five-number summary. b. Compute the lower and upper limits. c. Do the data contain any outliers? d. Johnson & Johnson’s sales are the large

> Naples, Florida, hosts a half-marathon (13.1-mile race) in January each year. The event attracts top runners from throughout the United States as well as from around the world. In the race results shown below 22 men and 31 women entered the 19â&#12

> A data set has a first quartile of 42 and a third quartile of 50. Compute the lower and upper limits for the corresponding boxplot. Should a data value of 65 be considered an outlier?

> Show the five-number summary and the boxplot for the following data: 5, 15, 18, 10, 8, 12, 16, 10, 6.

> Show the boxplot for the data in exercise 46. Exercise 46: Consider a sample with data values of 27, 25, 20, 15, 30, 34, 28, and 25. Provide the five-number summary for the data.

> Consider a sample with data values of 27, 25, 20, 15, 30, 34, 28, and 25. Provide the five-number summary for the data.

> The New York Times reported that Apple has unveiled a new iPad marketed specifically to school districts for use by students (The New York Times website). The 9.7-inch iPads will have faster processors and a cheaper price point in an effort to take marke

> A sample of 10 NCAA college basketball game scores provided the following data. a. Compute the mean and standard deviation for the points scored by the winning teams. b. Assume that the points scored by the winning teams for all NCAA games follow a bel

> The Northwest regional manager of an outdoor equipment retailer conducted a study to determine how managers at three store locations are using their time. A summary of the results are shown in the following table. a. Create a stacked bar chart with sto

> Consider the following survey results that show smartphone ownership by age. a. Construct a stacked bar chart to display the above survey data on type of mobile phone ownership. Use age category as the variable on the horizontal axis. b. Comment on the

> After deducting grants based on need, the average cost to attend the University of Southern California (USC) is $27,175. Assume the population standard deviation is $7400. Suppose that a random sample of 60 USC students will be taken from this population

> People often wait until middle age to worry about having a healthy heart. However, many studies have shown that earlier monitoring of risk factors such as blood pressure can be very beneficial (The Wall Street Journal). Having higher than normal blood pr

> The file Snow contains temperature and snowfall data for 51 major U.S. cities over 30 years. For example, the average low temperature for Columbus, Ohio, is 44 degrees and the average annual snowfall is 27.5 inches. a. Construct a scatter diagram with th

> A study on driving speed (miles per hour) and fuel efficiency (miles per gallon) for midsize automobiles resulted in the following data: a. Construct a scatter diagram with driving speed on the horizontal axis and fuel efficiency on the vertical axis.

> The following crosstabulation summarizes the data for two categorical variables, x and y. The variable x can take on values low, medium, or high and the variable y can take on values yes or no. a. Compute the row percentages. b. Construct a stacked per

> Consider the following data on two categorical variables. The first variable, x, can take on values A, B, C, or D. The second variable, y, can take on values I or II. The following table gives the frequency with which each combination occurs. a. Constr

> The following 20 observations are for two quantitative variables, x and y. a. Develop a scatter diagram for the relationship between x and y. b. What is the relationship, if any, between x and y?

> The U.S. Department of Energy’s Fuel Economy Guide provides fuel efficiency data for cars and trucks (Fuel Economy website). A portion of the data from 2018 for 341 compact, midsize, and large cars is shown in Table 2.13. The data set c

> Refer to Table 2.12. a. Prepare a crosstabulation of the data on Industry (rows) and Brand Revenue ($ billions). Use class intervals of 25 starting at 0 for Brand Revenue ($ billions). b. Prepare a frequency distribution for the data on Brand Revenue ($

> Each year Forbes ranks the world’s most valuable brands. A portion of the data for 82 of the brands in the 2013 Forbes list is shown in Table 2.12 (Forbes website). The data set includes the following variables: Brand: The name of the b

> The following crosstabulation shows the number of households (1000s) in each of the four regions of the United States and the number of households at each income level (U.S. Census Bureau website,https://www.census.gov/data/tables/time-series/demo/income

> The mean airfare for flights departing from Buffalo Niagara International Airport during the first three months of 2017 was $320.51. Assume the standard deviation for this population of fares is known to be $80. Suppose a random sample of 60 flights depa

> Recently, management at Oak Tree Golf Course received a few complaints about the condition of the greens. Several players complained that the greens are too fast. Rather than react to the comments of just a few, the Golf Association conducted a survey of

> The following crosstabulation shows the average speed of the 25 winners by year of the Daytona 500 automobile race (The World Almanac). a. Calculate the row percentages. b. What is the apparent relationship between average winning speed and year? What

> The Daytona 500 is a 500-mile automobile race held annually at the Daytona International Speedway in Daytona Beach, Florida. The following crosstabulation shows the automobile make by average speed of the 25 winners over a 25 year period (The World Alman

> The following observations are for two quantitative variables, x and y a. Develop a crosstabulation for the data, with x as the row variable and y as the column variable. For x use classes of 10–29, 30–49, and so on;

> The following data are for 30 observations involving two categorical variables, x and y. The categories for x are A, B, and C; the categories for y are 1 and 2. a. Develop a crosstabulation for the data, with x as the row variable and y as the column v

> The Flying Pig is a marathon (26.2 mile long) running race held every year in Cincinnati, Ohio. Suppose that the following data show the ages for a sample of 40 marathon runners. a. Construct a stretched stem-and-leaf display. b. Which age group had th

> Each year America.EDU ranks the best paying college degrees in America. The following data show the median starting salary, the mid-career salary, and the percentage increase from starting salary to mid-career salary for the 20 college degrees with the h

> The file EngineeringSalary contains the median starting salary and median mid-career salary (measured 10 years after graduation) for graduates from 19 engineering schools (The Wall Street Journal). Develop a stem-and-leaf display for both the median star

> Do you dislike waiting in line? Supermarket chain Kroger has used computer simulation and information technology to reduce the average waiting time for customers at 2300 stores. Using a new system called Que-Vision, which allows Kroger to better predict

> The website for the Bed and Breakfast Inns of North America gets approximately seven visitors per minute. Suppose the number of website visitors per minute follows a Poisson probability distribution. a. What is the mean time between visits to the website

> The mean time between failures (MTBF) is a common metric used to measure the performance of manufacturing systems. MTBF is the elapsed time between failures of a system during normal operations. The failures could be caused by broken machines or computer

> The following data show the year to date percent change (YTD % Change) for 30 stock-market indexes from around the world (The Wall Street Journal). a. What index has the largest positive YTD % Change? b. Using a class width of 5 beginning with â&

> A blackjack player at a Las Vegas casino learned that the house will provide a free room if play is for four hours at an average bet of $50. The player’s strategy provides a probability of .49 of winning on any one hand, and the player knows that there a

> Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has probability .75 of answering any question correctly. a. A student must answer 43

> A machine fills containers with a particular product. The standard deviation of filling weights is known from past data to be .6 ounce. If only 2% of the containers hold less than 18 ounces, what is the mean filling weight for the machine? That is, what

> According to the National Association of Colleges and Employers, the 2015 mean starting salary for new college graduates in health sciences was $51,541. The mean 2015 starting salary for new college graduates in business was $53,901 (National Association

> According to U.S. News & World Reports, 7 of the top 10 graduate schools of business have students with an average undergraduate grade point average (GPA) of 3.50 or higher. Suppose that we randomly select 2 of the top 10 graduate schools of business. a.

> A deck of playing cards contains 52 cards, four of which are aces. What is the probability that the deal of a five-card poker hand provides a. A pair of aces? b. Exactly one ace? c. No aces? d. At least one ace?

> Customer arrivals at a bank are random and independent; the probability of an arrival in any one-minute period is the same as the probability of an arrival in any other one-minute period. Answer the following questions, assuming a mean arrival rate of th

> A regional director responsible for business development in the state of Pennsylvania is concerned about the number of small business failures. If the mean number of small business failures per month is 10, what is the probability that exactly 4 small bu

> A new automated production process averages 1.5 breakdowns per day. Because of the cost associated with a breakdown, management is concerned about the possibility of having three or more breakdowns during a day. Assume that breakdowns occur randomly, tha

> Entrepreneur magazine ranks franchises using performance measures such as growth rate, number of locations, startup costs, and financial stability. The number of locations for 20 U.S. franchises follows (The World Almanac). Use classes 0â€&#

> Foot Locker uses sales per square foot as a measure of store productivity. Sales are currently running at an annual rate of $406 per square foot. You have been asked by management to conduct a study of a sample of 64 Foot Locker stores. Assume the standa

> Cars arrive at a car wash randomly and independently; the probability of an arrival is the same for any two time intervals of equal length. The mean arrival rate is 15 cars per hour. What is the probability that 20 or more cars will arrive during any giv

> Mahoney Custom Home Builders, Inc. of Canyon Lake, Texas, asked visitors to their website what is most important when choosing a home builder. Possible responses were quality, price, customer referral, years in business, and special features. Results sho

> PBS News Hour reported in 2014 that 39.4% of Americans between the ages of 25 and 64 have at least a two-year college degree (PBS website). Assume that 50 Americans between the ages of 25 and 64 are selected randomly. a. What is the expected number of pe

> Many companies use a quality control technique called acceptance sampling to monitor incoming shipments of parts, raw materials, and so on. In the electronics industry, component parts are commonly shipped from suppliers in large lots. Inspection of a sa

> According to a 2017 Gallup survey, the percentage of individuals in the United States who are invested in the stock market by age is as shown in the following table (Gallup website). Age Range ……………….. Percent of Individuals Invested in Stock Market 18

> A Pew Research Survey asked adults in the United States which technologies would be “very hard” to give up. The following responses were obtained: Internet 53%, smartphone 49%, email 36%, and land-line phone 28% (USA Today website). a. If 20 adult Intern

> The Knowles/Armitage (KA) group at Merrill Lynch advises clients on how to create a diversified investment portfolio. One of the investment alternatives they make available to clients is the All World Fund composed of global stocks with good dividend yie

> A bookstore at the Hartsfield-Jackson Airport in Atlanta sells reading materials (paper-back books, newspapers, magazines) as well as snacks (peanuts, pretzels, candy, etc.). A point-of-sale terminal collects a variety of information about customer purch

> The Car Repair Ratings website provides consumer reviews and ratings for garages in the United States and Canada. The time customers wait for service to be completed is one of the categories rated. The following table provides a summary of the wait-time

> The U.S. Coast Guard (USCG) provides a wide variety of information on boating accidents including the wind condition at the time of the accident. The following table shows the results obtained for 4401 accidents (USCG website, http://www.uscgboating.org/

> University endowments are financial assets that are donated by supporters to be used to provide income to universities. There is a large discrepancy in the size of university endowments. The following table provides a listing of many of the universities

> The Panama Railroad Company was established in 1850 to construct a railroad across the isthmus that would allow fast and easy access between the Atlantic and Pacific Oceans. The following table provides annual returns for Panama Railroad stock from 1853

> Automobiles traveling on a road with a posted speed limit of 55 miles per hour are checked for speed by a state police radar system. Following is a frequency distribution of speeds. Speed (miles per hour) ……………………………. Frequency 45–49 …………………………………………………

> The days to maturity for a sample of five money market funds are shown here. The dollar amounts invested in the funds are provided. Use the weighted mean to determine the mean number of days to maturity for dollars invested in these five money market fun

> Does a major league baseball team’s record during spring training indicate how the team will play during the regular season? Over a six-year period, the correlation coefficient between a team’s winning percentage in sp

> In 2014, the 32 teams in the National Football League (NFL) were worth, on average, $1.17 billion, 5% more than in 2013. The following data show the annual revenue ($ millions) and the estimated team value ($ millions) for the 32 NFL teams in 2014 (Forbe

> Travel + Leisure magazine provides an annual list of the 500 best hotels in the world. The magazine provides a rating for each hotel along with a brief description that includes the size of the hotel, amenities, and the cost per night for a double room.

> The data contained in the file FoodIndustry show the company/chain name, the average sales per store ($1000s), and the food segment industry for 47 restaurant chains (Quick Service Restaurant Magazine website). a. What was the mean U.S. sales per store f

> The following data represent a sample of 14 household incomes ($1000s). Answer the following questions based on this sample. a. What is the median household income for these sample data? b. According to a previous survey, the median annual household in

> Public transportation and the automobile are two methods an employee can use to get to work each day. Samples of times recorded for each method are shown. Times are in minutes. a. Compute the sample mean time to get to work for each method. b. Compute

> Smartphones have become ubiquitous for most people and have become the predominant means of communication among people. Consider the following data indicating the number of minutes in a month spent interacting with others via a smartphone for a sample of

> The London School of Economics and the Harvard Business School have conducted studies of how chief executive officers (CEOs) spend their time. These studies have found that CEOs spend many hours per week in meetings that include conference calls, busines

> U.S. companies lose $63.2 billion per year from workers with insomnia. Accordign to a 2013 article in the Wall Street Journal, workers lose an average of 7.8 days of productivity per year due to lack of sleep. The following data show the number of hours

> The average waiting time for a patient at an El Paso physician’s office is just over 29 minutes, well above the national average of 21 minutes. In order to address the issue of long patient wait times, some physician’s offices are using wait tracking sys

> A 2017 USA Today article reports that NCAA football coaches’ salaries have continued to increase in recent years (USA Today). The annual base salaries for the previous head football coach and the new head football coach at 23 schools are given in the fil

> Americans tend to dine out multiple times per week. The number of times a sample of 20 families dined out last week provides the following data. a. Compute the mean and median. b. Compute the first and third quartiles. c. Compute the range and interqua

> The budgeting process for a midwestern college resulted in expense forecasts for the coming year (in $ millions) of $9, $10, $11, $12, and $13. Because the actual expenses are unknown, the following respective probabilities are assigned: .3, .2, .25, .05

> A study by Forbes indicated that the five most common words appearing in spam emails are shipping!, today!, here!, available, and fingertips!. Many spam filters separate spam from ham (email not considered to be spam) through application of Bayes’ theor

> An oil company purchased an option on land in Alaska. Preliminary geologic studies assigned the following prior probabilities. P(high-quality oil) = .50 P(medium-quality oil) = .20 P(no oil) = .30 a. What is the probability of finding oil? b. After 200 f

> Many undergraduate students in the U.S. study abroad as part of their education. Assume that 60% of the undergraduate students who study abroad are female and that 49% of the undergraduate students who do not study abroad are female. a. Given a female un

> A company studied the number of lost-time accidents occurring at its Brownsville, Texas, plant. Historical records show that 6% of the employees suffered losttime accidents last year. Management believes that a special safety program will reduce such acc

> Cooper Realty is a small real estate company located in Albany, New York, specializing primarily in residential listings. They recently became interested in determining the likelihood of one of their listings being sold within a certain number of days. A

> Based on the total passenger traffic, the airports in the following list are the 20 busiest airports in North America in 2018 (The World Almanac). a. Which is busiest airport in terms of total passenger traffic? Which is the least busy airport in terms

> A large consumer goods company ran a television advertisement for one of its soap products. On the basis of a survey that was conducted, probabilities were assigned to the following events. B = individual purchased the product S = individual recalls seei

> The Pew Internet & American Life project conducted a survey that included several questions about how Internet users feel about search engines and other websites collecting information about them and using this information either to shape search resu

> Refer again to the data from the MBA new-matriculants survey in exercise 52. a. Given that a person applied to more than one school, what is the probability that the person is 24–26 years old? b. Given that a person is in the 36-and-ove

> An MBA new-matriculants survey provided the following data for 2018 students. a. For a randomly selected MBA student, prepare a joint probability table for the experiment consisting of observing the student’s age and whether the stude

> The U.S. Census Bureau serves as the leading source of quantitative data about the nation’s people and economy. The following crosstabulation shows the number of households (1000s) and the household income by the highest level of educat

> A survey to determine viewer response to a new television show obtained the following data. Rating ………….. Frequency Poor …………………………. 4 Below average ……………. 8 Average …………………… 11 Above average …………. 14 Excellent …………………. 13 a. What is the probability th

> A study of 31,000 hospital admissions in New York State found that 4% of the admissions led to treatment-caused injuries. One-seventh of these treatment-caused injuries resulted in death, and one-fourth were caused by negligence. Malpractice claims were

> Below are the results of a survey of 1364 individuals who were asked if they use social media and other websites to voice their opinions about television programs. a. What is the probability a respondent is female? b. What is the conditional probabilit

> A financial manager made two new investments— one in the oil industry and one in municipal bonds. After a one-year period, each of the investments will be classified as either successful or unsuccessful. Consider the making of the two investments as a ra

> A USA Today survey of adults aged 18 and older conducted by Princess Cruises asked how many days into your vacation does it take until you feel truly relaxed. The responses were as follows: 422—a day or less; 181—2 days; 80—3 days; 121—4 or more days; an

> CBSSports.com developed the Total Player Ratings system to rate players in the National Basketball Association (NBA) based upon various offensive and defensive statistics. The following data show the average number of points scored per game (PPG) for 50

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