Pew Research Center is a nonpartisan polling organization that provides information about issues, attitudes, and trends shaping America. In a poll, Pew researchers found that 73% of teens aged 13–17 have a smartphone, 15% have a basic phone and 12% have no phone. The study also asked the respondents how they communicated with their closest friend. Of those with a smartphone, 58% responded texting, 17% social media and 10% phone calls. Of those with no smartphone, 25% responded texting, 29% social media and 21% phone calls (Pew Research Center website, October 2015). a. One statistic (58%) concerned the use of texting to contact his/her closest friend, if the teen owns a smartphone. To what population is that applicable? b. Another statistic (25%) concerned the use of texting by those who do not own a smartphone. To what population is that applicable? c. Do you think the Pew researchers conducted a census or a sample survey to obtain their results? Why?
> 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
> 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
> 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
> Alexa is the popular virtual assistant developed by Amazon. Alexa interacts with users using artificial intelligence and voice recognition. It can be used to perform daily tasks such as making to-do lists, reporting the news and weather, and interacting
> One indicator of the level of economic hardship is the number of people who bring items to a pawnbroker. Assume that the number of people bringing items to a pawnshop per day in is normally distributed with a mean of 658. a. Suppose you learn that on 3%
> Motorola used the normal distribution to determine the probability of defects and the number of defects expected in a production process. Assume a production process produces items with a mean weight of 10 ounces. Calculate the probability of a defect
> The NCAA estimates that the yearly value of a full athletic scholarship at in-state public universities is $19,000. Assume the scholarship value is normally distributed with a standard deviation of $2100. a. For the 10% of athletic scholarships of least
> A business executive, transferred from Chicago to Atlanta, needs to sell her house in Chicago quickly. The executive’s employer has offered to buy the house for $210,000, but the offer expires at the end of the week. The executive does not currently have
> 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
> 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. Table 2.18:
> A doctor’s office staff studied the waiting times for patients who arrive at the office with a request for emergency service. The following data with waiting times in minutes were collected over a one-month period. Use classes of 0&ac
> 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. Table 2.18:
> 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 with 2000 in increments of 50 for Year Founded. For % Graduate, use
> 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
> 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
> 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;
> 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
> 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
> Construct a stem-and-leaf display for the following data. Use a leaf unit of 10.
> 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 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
> Consumer Reports evaluates products for consumers. The file CompactSUV contains the data shown in Table 1.8 for 15 compact sports utility vehicles (SUVs) from the 2018 model line (Consumer Reports website): Make—manufacturer Modelâ
> A sample of midterm grades for five students showed the following results: 72, 65, 82, 90, 76. Which of the following statements are correct, and which should be challenged as being too generalized? a. The average midterm grade for the sample of five stu
> A survey conducted by Better Homes and Gardens Real Estate LLC showed that one in five U.S. homeowners has either moved from their home or would like to move because their neighborhood or community isn’t ideal for their lifestyle (Better Homes and Garden
> A seven-year medical research study reported that women whose mothers took the drug diethylstilbestrol (DES) during pregnancy were twice as likely to develop tissue abnormalities that might lead to cancer as were women whose mothers did not take the drug
> A survey of 131 investment managers in Barron’s Big Money poll revealed the following: ● 43% of managers classified themselves as bullish or very bullish on the stock market. ● The average expected return over the next 12 months for equities was 11.2%. ●
> A Bloomberg Businessweek North American subscriber study collected data from a sample of 2861 subscribers. Fifty-nine percent of the respondents indicated an annual income of $75,000 or more, and 50% reported having an American Express credit card. a. Wh
> A random telephone survey of 1021 adults (aged 18 and older) was conducted by Opinion Research Corporation on behalf of CompleteTax, an online tax preparation and e-filing service. The survey results showed that 684 of those surveyed planned to file thei
> Construct a stem-and-leaf display for the following data.
> A manager of a large corporation recommends a $10,000 raise be given to keep a valued subordinate from moving to another company. What internal and external sources of data might be used to decide whether such a salary increase is appropriate?
> Skechers U.S.A., Inc., is a performance footwear company headquartered in Manhattan Beach, California. The sales revenue for Skechers over a four-year period are as follows: a. Are these cross-sectional or time-series data? b. Construct a bar graph simil
> The U.S. Census Bureau tracks sales per month for various products and services through its Monthly Retail Trade Survey. Figure 1.9 shows monthly jewelry sales in millions of dollars for 2016. a. Are the data quantitative or categorical? b. Are the data
> The following data show the number of rental cars in service (in thousands) for three rental car companies: Hertz, Avis, and Dollar over a three-year period (Auto Rental News website). a. Construct a time series graph for the years 2007 to 2010 showing
> Figure 1.8 provides a bar chart showing the annual advertising revenue for Facebook from 2010 to 2017 (Facebook Annual Reports). a. What is the variable of interest? b. Are the data categorical or quantitative? c. Are the data time series or cross-sectio
> The Hawaii Visitors Bureau collects data on visitors to Hawaii. The following questions were among 16 asked in a questionnaire handed out to passengers during incoming airline flights. ● This trip to Hawaii is my: 1st, 2nd, 3rd, 4th, etc. ● The primary r
> A Gallup Poll utilizing a random sample of 1,503 adults ages 18 or older was conducted in April 2018. The survey indicated a majority of Americans (53%) say driverless cars will be common in the next 10 years (Gallup, https://news.gallup.com/poll/234152/
> The Bureau of Transportation Statistics Omnibus Household Survey is conducted annually and serves as an information source for the U.S. Department of Transportation. In one part of the survey the person being interviewed was asked to respond to the follo
> Based on data from the U.S. Census Bureau, a Pew Research study showed that the percentage of employed individuals ages 25–29 who are college educated is at an all-time high. The study showed that the percentage of employed individuals aged 25–29 with at
> The Tennessean, an online newspaper located in Nashville, Tennessee, conducts a daily poll to obtain reader opinions on a variety of current issues. In a recent poll, 762 readers responded to the following question: “If a constitutional amendment to ban
> Consider the following data. a. Construct a dot plot. b. Construct a frequency distribution. c. Construct a percent frequency distribution.
> 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
> 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? Table 1.7:
> Table 1.7 shows data for eight phones (Consumer Reports). The Overall Score, a measure of the overall quality for the phone, ranges from 0 to 100. Voice Quality has possible ratings of poor, fair, good, very good, and excellent. Talk Time is the manufac
> 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. What percentage of tablets use a CPU manufactured
> Tablet PC Comparison provides a wide variety of information about tablet computers. The company’s website enables consumers to easily compare different tablets using factors such as cost, type of operating system, display size, battery
> 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.
> Assume that we want to identify a simple random sample of 12 of the 372 doctors practicing in a particular city. The doctors’ names are available from a local medical organization. Use the eighth column of five-digit random numbers in T
> Construct a histogram for the data in exercise 12. Exercise 12: Consider the following frequency distribution. Class ……………………………….. Frequency 10–19 …………………………………………. 10 20–29 ………………………………………… 14 30–39 …………………………………………. 17 40–49 …………………………………………. 7 50–5
> 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
> 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
> According to the U.S. Department of Health and Human Services, only 49.2% of homes in the United States used landline telephone service in 2017. a. Suppose a sample of 207,000 U.S. homes will be taken to learn about home telephone usage. Show the samplin
> The president of Colossus.com, Inc., believes that 42% of the firm’s orders come from customers who have purchased from Colossus.com in the past. A random sample of 108,700 orders from the past six months will be used to estimate the proportion of orders
> The New York Times reported that 17.2 million new cars and light trucks were sold in the United States in 2017, and the U.S. Environmental Protection Agency projects the average efficiency for these vehicles to be 25.2 miles per gallon. Assume that that
> The U.S. Bureau of Labor Statistics (BLS) reported that the mean annual number of hours of vacation time earned by blue-collar and service employees who work for small private establishments and have at least 10 years of service is 100. Assume that for t
> Assume that the population proportion is .44. Compute the standard error of the proportion, σp̅, 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 Proportio
> A sample of size 100,000 is selected from a population with p = .75. a. What is the expected value of p̅? b. What is the standard error of p̅? c. Show the sampling distribution of p̅. d. What does the sampling distribution of p̅ show?
> Assume the population standard deviation is σ = 25. Compute the standard error of the mean, σx̅, 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 mean as the samp
> A population has a mean of 400 and a standard deviation of 100. A sample of size 100,000 will be taken, and the sample mean x̅ will be used to estimate the population mean. a. What is the expected value of x̅? b. What is the standard deviation of x̅ ? c
> Consider the following frequency distribution. Class ……………………………….. Frequency 10–19 …………………………………………. 10 20–29 ………………………………………… 14 30–39 …………………………………………. 17 40–49 …………………………………………. 7 50–59 …………………………………………. 2 Construct a cumulative frequency distribut
> Data made available through the Petersen-Kaiser Health System Tracker in May 2018 showed health expenditures were $10,348 per person in the United States. Use $10,348 as the population mean and suppose a survey research firm will take a sample of 100 peo
> The Food Marketing Institute shows that 17% of households spend more than $100 per week on groceries. Assume the population proportion is p = .17 and a sample of 800 households will be selected from the population. a. Show the sampling distribution of p̅
> The Grocery Manufacturers of America reported that 76% of consumers read the ingredients listed on a product’s label. Assume the population proportion is p = .76 and a sample of 400 consumers is selected from the population. a. Show the sampling distribu
> 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 Ta
> In 2016 the Better Business Bureau settled 80% of complaints they received in the United States. Suppose you have been hired by the Better Business Bureau to investigate the complaints they received this year involving new car dealers. You plan to select
> According to Reader’s Digest, 42% of primary care doctors think their patients receive unnecessary medical care. a. Suppose a sample of 300 primary care doctors was taken. Show the sampling distribution of the proportion of the doctors who think their pa
> In 2017, the Restaurant Hospitality website reported that only 10% of surplus food is being recovered in the food-service and restaurant sector, leaving approximately 1.5 billion meals per year uneaten. Assume this is the true population proportion and t
> The Wall Street Journal reported that the age at first startup for 55% of entrepreneurs was 29 years of age or less and the age at first startup for 45% of entrepreneurs was 30 years of age or more. a. Suppose a sample of 200 entrepreneurs will be taken
> The president of Doerman Distributors, Inc., believes that 30% of the firm’s orders come from first-time customers. A random sample of 100 orders will be used to estimate the proportion of first-time customers. a. Assume that the president is correct and
> The population proportion is .30. What is the probability that a sample proportion will be within ±.04 of the population proportion for each of the following sample sizes? a. n = 100 b. n = 200 c. n = 500 d. n = 1000 e. What is the advantage of a larger
> Assume that the population proportion is .55. Compute the standard error of the proportion, σp̅, 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?
> Consider the following data. a. Develop a frequency distribution using classes of 12–14, 15–17, 18–20, 21–23, and 24–26. b. Develop a relative frequency distribut