What is the difference between a permutation and a combination?
> If P(A) = 0.3, P(B) = 0.4, and P(A and B) = 0.2, are A and B independent?
> The article mentioned in Problem 7.30 reported that the stock market in Germany had a mean return of 6.9% in 2016. Assume that the returns for stocks on the German stock market were distributed normally, with a mean of 6.9 and a standard deviation of 10.
> a. If a coin is tossed seven times, how many different outcomes are possible? b. If a die is tossed seven times, how many different outcomes are possible? c. Discuss the differences in your answers to (a) and (b).
> If P(A) = 0.7, P(B) = 0.6, and A and B are independent, find P(A and B).
> If P(A and B) = 0.4 and P(B) = 0.8, find P(AB).
> In 2015, the per capita consumption of soft drinks in the United States was reported to be 650 eight-ounce servings. Source: Data extracted from fortune.com/2016/03/29/soda-sales-drop-11th-year. Assume that the per capita consumption of soft drinks in th
> Consider the following contingency table: What is the probability of a. AB? b. A= B=? c. AB=? d. Are events A and B independent? B B' A 10 30 A' 25 35
> Consider the following contingency table: What is the probability of a. A | B? b. A | Bâ€™? c. Aâ€™ | Bâ€™? d. Are events A and B independent? B B' A 10 20 A' 20 40
> Each year, ratings are compiled concerning the performance of new cars during the first 90 days of use. Suppose that the cars have been categorized according to whether a car needs a warranty-related repair (yes or no) and the country in which the compan
> The following table represents the market share (in number of movies, gross in millions of dollars, and millions of tickets sold) of each type of movie in 2016: a. Construct a bar chart, a pie chart, a doughnut chart, and a Pareto chart for the number
> According to a report by App Annie, a business intelligence company that produces tools and reports for the apps and digital goods industry, smartphone owners are using an average of 30 apps per month. Source: “Report: Smartphone owners are using 9 apps
> The following table shown in the file TextbookCosts shows the breakdown of the costs of a typical college textbook. a. Using the categories of publisher, bookstore, and author, construct a bar chart, a pie chart, and a Pareto chart. b. Using the subcat
> What is the difference between a time-series plot and sparklines?
> What is the difference between a drill-down and a slicer?
> What type of insights can you gain from a contingency table that contains three variables that you cannot gain from a contingency table that contains two variables?
> How can a multidimensional table differ from a two-variable contingency table?
> What are the three different ways to break down the percentages in a contingency table?
> Why is it said that the main feature of a Pareto chart is its ability to separate the “vital few” from the “trivial many”?
> A survey of 1,520 Americans adults asked, “Do you feel overloaded with too much information?” The results indicated that of 785 males, 134 answered yes. Of 735 females, 170 answered yes. Source: Data extracted from “Information Overload,” pewrsr.ch/2h2OS
> What is the difference between a time-series plot and a scatter plot?
> For each of the following three populations, indicate what the sampling distribution for samples of 25 would consist of: a. Customer receipts for a supermarket for a year. b. Insurance payouts in a particular geographical area in a year. c. Call cente
> A set of final examination grades in an introductory statistics course is normally distributed, with a mean of 73 and a standard deviation of 8. a. What is the probability that a student scored below 91 on this exam? b. What is the probability that a s
> The file DomesticBeer contains the percentage alcohol, number of calories per 12 ounces, and number of carbohydrates (in grams) per 12 ounces for 158 of the best-selling domestic beers in the United States. Source: Data extracted from bit.ly/1A4E6AF, De
> You are planning to study for your statistics examination with a group of classmates, one of whom you particularly want to impress. This individual has volunteered to use Microsoft Excel to generate the needed summary information, tables, and charts for
> The U.S. Census Bureau announced that the median sales price of new houses sold in 2016 was $316,500, and the mean sales price was $370,800 Source: www.census.gov/newhomesales, April 1, 2017. Assume that the standard deviation of the prices is $90,000.
> How do the mean credit scores of people living in various American cities differ? The file Credit Scores is an ordered array of the average credit scores of people living in 2,570 American cities. Source: Data extracted from “Study shows cities with high
> How much time do commuters living in or near cities spend commuting to work each week? The file CommutingTime contains the average weekly commuting time in 30 U.S. cities. Source: Data extracted from New York City Economics Brief, March 2015, p. 3. For t
> 311 is Chicago’s web and phone portal for government information and nonemergency services. 311 serves as a comprehensive one-stop shop for residents, visitors, and business owners; therefore, it is critical that 311 representatives answer calls and resp
> Have you wondered how Internet connection speed varies around the globe? The file ConnectionSpeed contains the mean connection speed, the mean peak connection speed, the % of the time the speed is above 4 Mbs, and the % of the time the connection speed i
> Do Generation X and Boomers differ in how they use credit cards? A sample of 1,000 Generation X and 1,000 Boomers revealed the following results: Source: Data extracted from â€œC. Jones, â€œGen X, Boomers see Credit Card
> The file Property Taxes contains the property taxes on a $176K home and the median home value ($000) for the 50 states and the District of Columbia. For each of these two variables: a. Compute the mean, median, first quartile, and third quartile. b. Co
> What was the mean price of a room at two-star, three-star, and four-star hotels in the major cities of the world during 2016? The file HotelPrices contains the prices in Canadian dollars (about US $0.75 as of December 2016). Source: Data extracted from “
> The file Protein contains calories, protein, and cholesterol of popular protein foods (fresh red meats, poultry, and fish). Source: U.S. Department of Agriculture. a. Compute the correlation coefficient between calories and protein. b. Compute the corr
> Millennials spent an average of $103 on monthly dining in 2016. Source: Data extracted from Consumer Response Annual Report,available at bit.ly/2x4CN5w. Assume that the amount spent on a monthly dining is normally distributed and that the standard devia
> Referring to the contingency table in Problem 4.8, if an employed adult is selected at random, what is the probability that a. the employed adult felt tense or stressed out at work? b. the employed adult was a millennial who felt tense or stressed out at
> The file Restaurants contains the cost per meal and the ratings of 50 center city and 50 metro area restaurants on their food, décor, and service (and their summated ratings). Source: Data extracted from Zagat Survey 2016 New York City Restaurants. Compl
> The manufacturer of Boston and Vermont asphalt shingles provides its customers with a 20-year warranty on most of its products. To determine whether a shingle will last as long as the warranty Chapter Review Problems 157 period, accelerated-life testing
> A quality characteristic of interest for a tea-bag-filling process is the weight of the tea in the individual bags. If the bags are underfilled, two problems arise. First, customers may not be able to brew the tea to be as strong as they wish. Second, th
> The diameter of a brand of tennis balls is approximately normally distributed, with a mean of 2.63 inches and a standard deviation of 0.03 inch. If you select a random sample of nine tennis balls, a. what is the sampling distribution of the mean? b. wh
> Data were collected on the typical cost of dining at Americancuisine restaurants within a 1-mile walking distance of a hotel located in a large city. The file Bundle contains the typical cost (a per transaction cost in $) as well as a Bundle score, a mea
> Have the gains in student learning attributed to education technology justified collegesâ€™ spending in this area? As part of Inside Higher Edâ€™s 2016 Survey of Faculty Attitudes on Technology, academic professionals, pro
> The financial services call center in Problem 3.66 also monitors call duration, which is the amount of time spent speaking to customers on the phone. The file CallDuration contains the following data for time, in seconds, spent by agents talking to 50 cu
> The CMO Survey collects and disseminates the opinions of top marketers in order to predict the future of markets, track marketing excellence, and improve the value of marketing in firms and in society. Part of the survey is devoted to the topic of market
> Content Marketing Institute provides insights on the content marketing habits of nonprofit professionals representing a broad range of nonprofit agencies and organizations. A survey of nonprofit marketers conducted by the Content Marketing Institute indi
> To better understand the website builder market, Clutch surveyed individuals who created a website using a do-it-yourself (DIY) website builder. Respondents, categorized by the type of website they builtâ€”business or personal, were asked
> Toby’s Trucking Company determined that the distance traveled per truck per year is normally distributed, with a mean of 50 thousand miles and a standard deviation of 12 thousand miles. a. What proportion of trucks can be expected to travel between 34 an
> Chartered Institute of Personnel and Development (CIPD) provides commentary and insight about the trends and challenges facing the HR profession in its HR Outlook Report. The report represents the results of an online survey conducted in 2016 with HR pro
> Do Millennials or Gen-Xers feel more tense or stressed out at work? A survey of employed adults conducted online by Harris Interactive on behalf of the American Psychological Association revealed the following: Source: Data extracted from â€
> A survey by Accenture indicated that 64% of millennials as compared to 28% of baby boomers prefer “hybrid” investment advice—a combination of traditional advisory services and low-cost digital tools—over either a dedicated human advisor or conventional r
> What is the difference between Counting Rule 1 and Counting Rule 2?
> Referring to the contingency table in Problem 4.10, if a marketer is selected at random, what is the probability that a. he or she plans to increase use of LinkedIn? b. he or she is a B2C marketer? c. he or she plans to increase use of LinkedIn or is a B
> In Bayes’ theorem, how does the prior probability differ from the revised probability?
> The weight of an energy bar is approximately normally distributed with a mean of 42.05 grams with a standard deviation of 0.025 gram. a. What is the probability that an individual energy bar contains less than 42.035 grams? b. If a sample of 4 energy b
> How can you use Bayes’ theorem in light of new information?
> How does the multiplication rule differ for events that are and are not independent?
> How does conditional probability relate to the concept of independence?
> In 2015, the per capita consumption of bottled water in the United States was reported to be 36.2 gallons. Source: Data extracted from bottledwater.org/economics/bottled-water-market. Assume that the per capita consumption of bottled water in the United
> What is the difference between mutually exclusive events and collectively exhaustive events?
> How can you use the general addition rule to find the probability of occurrence of event A or B?
> Which of the following events occur with a probability of zero? For each, state why or why not. a. A company is listed on the New York Stock Exchange and NASDAQ. b. A consumer owns a smartphone and a tablet. c. A cellphone is an Apple and a Samsung. d. A
> What is the difference between a simple event and a joint event?
> How will marketers change their social media use in the near future? A survey by Social Media Examiner reported that 76% of B2B marketers (marketers that focus primarily on attracting businesses) plan to increase their use of LinkedIn, as compared to 52%
> What are the differences between a priori probability, empirical probability, and subjective probability?
> There are 15 exercise bikes in a fitness store showroom. The fitness store owner wishes to select three of them to display at a fitness expo. How many ways can a group of three be selected?
> A daily lottery is conducted in which 2 winning numbers are selected out of 100 numbers. How many different combinations of winning numbers are possible?
> A student has seven books that she would like to place in her backpack. However, there is room for only four books. Regardless of the arrangement, how many ways are there of placing four books into the backpack?
> The amount of water in a two-liter bottle is approximately normally distributed with a mean of 2.05 liters with a standard deviation of 0.025 liter. a. What is the probability that an individual bottle contains less than 2.03 liters? b. If a sample of
> Four members of a group of 10 people are to be selected to a team. How many ways are there to select these four members?
> Given a normal distribution with m = 50 and s = 4, what is the probability that a. X > 43? b. X < 42? c. Five percent of the values are less than what X value? d. Between what two X values (symmetrically distributed around the mean) are 60 percent of the
> How many different ways can a senior project manager and an associate project manager be selected for an analytics project if there are eight data scientists available?
> A gardener has six rows available in his vegetable garden to place tomatoes, eggplant, peppers, cucumbers, beans, and lettuce. Each vegetable will be allowed one and only one row. How many ways are there to position these vegetables in this garden?
> Referring to Problem 4.44 how many different orders of finish are possible for the first four positions?
> The file McDonaldsStores contains the number of McDonald’s stores located in each of the 50 U.S. states and the District of Columbia, as of December 31, 2016: Source: Data extracted from bit.ly/2qJjFpF. a. Compute the mean, variance, and standard deviati
> For each of the following, state whether the events created are mutually exclusive and whether they are collectively exhaustive. a. Undergraduate business students were asked whether they were sophomores or juniors. b. Each respondent was classified by t
> The United Auto Courts Reports blog notes that the National Insurance Crime Bureau says that Miami-Dade, Broward, and Palm Beach counties account for a substantial number of questionable insurance claims referred to investigators. Assume that the number
> Spurious correlation refers to the apparent relationship between variables that either have no true relationship or are related to other variables that have not been measured. One widely publicized stock market indicator in the United States that is an e
> One theory concerning the S&P 500 Index is that if it increases during the first five trading days of the year, it is likely to increase during the entire year. From 1950 through 2016, the S&P 500 Index had these early gains in 42 years (in 2011 there wa
> According to the same Glassdoor source mentioned in Problem 6.40, the mean monthly pay for interns at Facebook is $6,589. Suppose that the intern monthly pay is normally distributed, with a standard deviation of $500. What is the probability that the mon
> Interns report that when deciding on where to work, career growth, salary and compensation, location and commute, and company culture and values are important factors to them. According to reports by interns to Glassdoor, the mean monthly pay of interns
> The fill amount in 2-liter soft drink bottles is normally distributed, with a mean of 2.0 liters and a standard deviation of 0.05 liter. If bottles contain less than 95% of the listed net content (1.90 liters, in this case), the manufacturer may be subje
> Given a normal distribution with m = 100 and s = 10, what is the probability that a. X > 75? b. X < 70? c. X < 80 or X > 110? d. Between what two X values (symmetrically distributed around the mean) are 80 percent of the values?
> An industrial sewing machine uses ball bearings that are targeted to have a diameter of 0.75 inch. The lower and upper specification limits under which the ball bearings can operate are 0.74 inch and 0.76 inch, respectively. Past experience has indicated
> How can you use the normal probability plot to evaluate whether a set of data is normally distributed?
> The file CDRate contains the yields for one-year certificates of deposit (CDs) and for five-year CDs for 39 banks in the United States, as of January 9, 2017. Source: Data extracted and compiled from www.bankrate.com, January 9, 2017. a. Construct a ste
> How does the shape of the normal distribution differ from the shapes of the uniform and exponential distributions?
> The major stock market indexes had strong results in 2016. The mean one-year return for stocks in the S&P 500, a group of 500 very large companies, was +9.54%. The mean one-year return for Chapter Review Problems 245 246 CHAPTER 6 | The Normal Distributi
> For each of the following, indicate whether the type of probability involved is an example of a priori probability, empirical probability, or subjective probability. a. The next toss of a fair coin will land on heads. b. Italy will win soccer’s World Cup
> The following data represent the number of days absent per year in a population of six employees of a small company: 1 3 6 7 9 10 a. Assuming that you sample without replacement, select all possible samples of n = 2 and construct the sampling distributi
> What are some of the distinguishing properties of a normal distribution?
> How do you find the X value that corresponds to a given percentile of the normal distribution?
> How do you find the area between two values under the normal curve?
> The scheduled commuting time on the Long Island Railroad from Glen Cove to New York City is 65 minutes. Suppose that the actual commuting time is uniformly distributed between 64 and 74 minutes. What is the probability that the commuting time will be a.
> Given a standardized normal distribution (with a mean of 0 and a standard deviation of 1, as in Table E.2), determine the following probabilities: a. P(Z > 1.08) b. P(Z < -0.21) c. P(-1.96 < Z < -0.21) d. What is the value of Z if only 15.87 percent of a
> How long does it take to download a two-hour HD movie from the iTunes store? According to Apple’s technical support site, support.apple.com/en-us/HT201587, downloading such a movie using a 15 Mbit/s broadband connection should take 29–43 minutes. Assume
> Nielsen study indicates that 18- to 34-year olds spend a mean of 93 minutes watching video on their smartphones per week. Source: Data extracted from bit.ly/2rj8GHm. Assume that the amount of time watching video on a smartphone per week is normally dist
> A study of the time spent shopping in a supermarket for a market basket of 20 specific items showed an approximately uniform distribution between 20 minutes and 40 minutes. What is the probability that the shopping time will be a. between 25 and 30 minut
> The time between arrivals of customers at a bank during the noon-to-1 P.M. hour has a uniform distribution between 0 to 120 seconds. What is the probability that the time between the arrival of two customers will be a. less than 20 seconds? b. between 10
> Suppose you select one value from a uniform distribution with a = 0 and b = 10. What is the probability that the value will be a. between 5 and 7? b. between 2 and 3? c. What is the mean? d. What is the standard deviation?
> The file Utility contains the electricity costs, in dollars, during July of a recent year for a random sample of 50 one-bedroom apartments in a large city: 96 171 202 178 147 102 153 197 127 82 157 185 90 116 172 111 148 213 130 165 141 149 206 175 1
> Consider the following contingency table: What is the probability of event a. A? b. A and B? c. A and B? d. A or B? в B' A 10 30 A' 25 35