The SAT is a standardized test used by many colleges and universities in their admission decisions. More than one million high school students take the SAT each year. The current version of the SAT includes three parts: reading comprehension, mathematics, and writing. A perfect combined score for all three parts is 2400. A sample of SAT scores for the combined three-part SAT are as follows:
a. Show a frequency distribution and histogram. Begin with the first class starting at 800 and use a class width of 200.
b. Comment on the shape of the distribution.
c. What other observations can be made about the SAT scores based on the tabular and graphical summaries?
> 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€&#
> 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). Suppose Gallup wishes to complete a follow-up survey to find out more
> 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
> Bookstore Customer Purchases. 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 in
> 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’ the
> 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
> 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
> 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
> 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
> 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
> 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-over age group, what
> 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 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 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
> 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
> 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 63
> 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
> 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
> 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
> The XO Group Inc. conducted a 2015 survey of 13,000 brides and grooms married in the United States and found that the average cost of a wedding is $29,858 (XO Group website). Assume that the cost of a wedding is normally distributed with a mean of $29,85
> 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
> A survey to determine viewer response to a new television show obtained the following data. a. What is the probability that a randomly selected viewer will rate the new show as average or better? b. What is the probability that a randomly selected view
> 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
> Below are the results of a survey of 1364 individuals who were asked if they use a. What is the probability a respondent is female? b. What is the conditional probability a respondent uses social media and other websites to voice opinions about televisi
> Ward Doering Auto Sales is considering offering a special service contract that will cover the total cost of any service work required on leased vehicles. From experience, the company manager estimates that yearly service costs are approximately normally
> 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
> Busiest North American Airports. 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 i
> 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
> 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
> 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
> The proportion of individuals insured by the All-Driver Automobile Insurance Company who received at least one traffic ticket during a five-year period is .15. a. Show the sampling distribution of p if a random sample of 150 insured individuals is used t
> Advertisers contract with Internet service providers and search engines to place ads on websites. They pay a fee based on the number of potential customers who click on their ad. Unfortunately, click fraud—the practice of someone clicking on an ad solely
> A market research firm conducts telephone surveys with a 40% historical response rate. What is the probability that in a new sample of 400 telephone numbers, at least 150 individuals will cooperate and respond to the questions? In other words, what is th
> A researcher reports survey results by stating that the standard error of the mean is 20. The population standard deviation is 500. a. How large was the sample used in this survey? b. What is the probability that the point estimate was within ±25 of the
> A production process is checked periodically by a quality control inspector. The inspector selects simple random samples of 30 finished products and computes the sample mean product weights x. If test results over a long period of time show that 5% of th
> 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
> 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
> 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 seeing t
> Consumer complaints are frequently reported to the Better Business Bureau (BBB). Some industries against whom the most complaints are reported to the BBB are banks; cable and satellite television companies; collection agencies; cellular phone providers;
> Data showing the population by state in millions of people follow (The World Almanac). a. Develop a frequency distribution, a percent frequency distribution, and a histogram. Use a class width of 2.5 million. b. Does there appear to be any skewness in
> The file MedianHousehold contains the median household income for a family with two earners for each of the fifty states (American Community Survey). a. Construct a frequency and a percent frequency distribution of median household income. Begin the firs
> 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. a. What is the mean speed of the automobiles traveling on this road? b
> 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
> 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 ($1000s), and the food segment industry for 47 restaurant chains (Quick Service Restaurant Magazine website). a. What was the mean U.S. sales per store f
> Revenue of World’s Most Valuable Brands. Refer to Table 2.12. a. Prepare a crosstabulation of the data on Industry (rows) and Brand Revenue ($ billions). Use class intervals of 25 starting at 0 for Brand Revenue ($ billions). b. Prepa
> 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 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
> 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 interquar
> A zoo has categorized its visitors into three categories: member, school, and general. The member category refers to visitors who pay an annual fee to support the zoo. Members receive certain benefits such as discounts on merchandise and trips planned by
> Electric plug-in vehicle sales have been increasing worldwide. The table below displays data collected by the U.S. Department of Energy on electric plug-in vehicle sales in the words top markets in 2013 and 2015. (Data compiled by Argonne National Labora
> Colleges’ Year Founded and Percent Graduated. Refer to the data set in Table 2.18. a. Construct a crosstabulation with Year Founded as the row variable and % Graduate as the column variable. Use classes starting with 1600 and ending w
> Table 2.18 shows a portion of the data for a sample of 103 private colleges and universities. The complete data set is contained in the file Colleges. The data include the name of the college or university, the year the institution was founded, the tuiti
> 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
> Fortune magazine publishes an annual survey of the 100 best companies to work for. The data in the file FortuneBest100 shows the rank, company name, the size of the company, and the percentage job growth for full-time employees for 98 of the Fortune 100
> Western University has only one women’s softball scholarship remaining for the coming year. The final two players that Western is considering are Allison Fealey and Emily Janson. The coaching staff has concluded that the speed and defen
> 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 level of education for
> The term “beta” refers to a measure of a stock’s price volatility relative to the stock market as a whole. A beta of 1 means the stock’s price moves exactly with the market. A beta o
> Colleges’ Year Founded and Cost. Refer to the data set in Table 2.18. a. Construct a scatter diagram to show the relationship between Year Founded and Tuition & Fees. b. Comment on any relationship between the variables.
> According to the Wall Street Journal, a startup company’s ability to gain funding is a key to success. The funds raised (in millions of dollars) by 50 startup companies appear below. a. Construct a stem-and-leaf display. b. Comment on
> 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
> 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
> 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
> Colleges’ Cost and Percent Graduated. Refer to the data set in Table 2.18. a. Prepare a scatter diagram to show the relationship between Tuition & Fees and % Graduate. b. Comment on any relationship between the variables.
> 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/inco
> Many service companies collect data via a follow- up survey of their customers. For example, to ascertain customer sentiment, Delta Air Lines sends an email to customers immediately following a flight. Among other questions, Delta asks: How likely are yo
> J.D. Power and Associates surveys new automobile owners to learn about the quality of recently purchased vehicles. The following questions were asked in a J.D. Power Initial Quality Survey. a. Did you purchase or lease the vehicle? b. What price did you
> Summarizing Phone Data. Refer to the data set in Table 1.7. a. What is the average price for the phones? b. What is the average talk time for the phones? c. What percentage of the phones have a voice quality of excellent?
> In a recent report, the top five most-visited English-language websites were google.com (GOOG), facebook.com (FB), youtube.com (YT), yahoo. com (YAH), and wikipedia.com (WIKI). The most-visited websites for a sample of 50 Internet users are shown in the
> A questionnaire provides 58 Yes, 42 No, and 20 no-opinion answers. a. In the construction of a pie chart, how many degrees would be in the section of the pie showing the Yes answers? b. How many degrees would be in the section of the pie showing the No a
> A partial relative frequency distribution is given. a. What is the relative frequency of class D? b. The total sample size is 200. What is the frequency of class D? c. Show the frequency distribution. d. Show the percent frequency distribution.
> Discuss the differences between statistics as numerical facts and statistics as a discipline or field of study.
> The Wall Street Journal provides the net asset value, the year-to-date percent return, and the three-year percent return for 882 mutual funds at the end of 2017. Assume that a simple random sample of 12 of the 882 mutual funds will be selected for a foll
> The following stocks make up the Dow Jones Industrial Average. Suppose you would like to select a sample of six of these companies to conduct an indepth study of management practices. Use the first two digits in each row of the ninth column of Table 7.1
> The County and City Data Book, published by the Census Bureau, lists information on 3139 counties throughout the United States. Assume that a national study will collect data from 30 randomly selected counties. Use four-digit random numbers from the last
> 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
> A student government organization is interested in estimating the proportion of students who favor a mandatory “pass-fail” grading policy for elective courses. A list of names and addresses of the 645 students enrolled
> Assume that the population proportion is .44. Compute the standard error of the proportion, , for sample sizes of 500,000; 1,000,000; 5,000,000; 10,000,000; and 100,000,000. What can you say about the size of the standard error of the sample proportion
> The 10 most active stocks on the New York Stock Exchange for a given week, are shown here. Exchange authorities decided to investigate trading practices using a sample of three of these stocks. a. Beginning with the first random digit in column 6 of Tab
> Assume that the population proportion is .55. Compute the standard error of the proportion, , for sample sizes of 100, 200, 500, and 1000. What can you say about the size of the standard error of the proportion as the sample size is increased?
> A sample of size 100 is selected from a population with / = .40. a. What is the expected value of /? b. What is the standard error of /? c. Show the sampling distribution of /. d. What does the sampling distribution of / show?
> Fortune publishes data on sales, profits, assets, stockholders’ equity, market value, and earnings per share for the 500 largest U.S. industrial corporations every year. Assume that you want to select a simple random sample of 10 corpor
> Assume the population standard deviation is s = 25. Compute the standard error of the mean, sx, for sample sizes of 50, 100, 150, and 200. What can you say about the size of the standard error of the mean as the sample size is increased?
> The Pew American Trends Survey includes a series of questions on attitudes toward automation. The May 2018 results showed that 2977 of 4135 respondents are worried about a future in which robots and computers can do many human jobs, 2770 are worried abou
> According to Wine-Searcher, wine critics generally use a wine-scoring scale to communicate their opinions on the relative quality of wines. Wine scores range from 0 to 100, with a score of 95–100 indicating a great wine, 90â€
> Morningstar publishes ratings data on 1208 company stocks. A sample of 40 of these stocks is contained in the file Morningstar. Use the Morningstar data set to answer the following questions. a. Develop a point estimate of the proportion of the stocks th
> 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
> Tablet PCs: Cost, CPU, and Operating System. Refer to Table 1.6. a. What is the average cost for the tablets? b. Compare the average cost of tablets with a Windows operating system to the average cost of tablets with an Android operating system. c. Wha