A municipal bond service has three rating categories (A, B, and C). Suppose that in the past year, of the municipal bonds issued throughout the United States, 70% were rated A, 20% were rated B, and 10% were rated C. Of the municipal bonds rated A, 50% were issued by cities, 40% by suburbs, and 10% by rural areas. Of the municipal bonds rated B, 60% were issued by cities, 20% by suburbs, and 20% by rural areas. Of the municipal bonds rated C, 90% were issued by cities, 5% by suburbs, and 5% by rural areas. a. If a new municipal bond is to be issued by a city, what is the probability that it will receive an A rating? b. What proportion of municipal bonds are issued by cities? c. What proportion of municipal bonds are issued by suburbs?
> Webrooming, researching products online before buying them in store, has become the new norm for some consumers and contrasts with showrooming, researching products in a physical store before purchasing online. A recent study by Interactions reported tha
> What are the four properties that must be present in order to use the binomial distribution?
> What is the meaning of the expected value of a variable?
> 5.29 A toll-free phone number is available from 9 a.m. to 9 p.m. for your customers to register complaints about a product purchased from your company. Past history indicates that a mean of 0.8 calls is received per minute. a. What properties must be tr
> One of the major measures of the quality of service provided by an organization is the speed with which the organization responds to customer complaints. A large family-held department store selling furniture and flooring, including carpet, had undergone
> As player salaries have increased, the cost of attending basketball games has increased dramatically. The file NBACost contains the cost of four tickets purchased on the secondary market, two beers, two soft drinks, four hot dogs, and one parking space a
> Refer to Problem 5.27. If you purchased a Toyota in the 2016 model year, what is the probability that in the past 12 months the car had a. zero problems? b. two or fewer problems? c. Compare your answers in (a) and (b) to those for the Ford in Problem
> J.D. Power and Associates calculates and publishes various statistics concerning car quality. The dependability score measures problems experienced during the past 12 months by owners of vehicles (2016). For these models of cars, Ford had 1.02 problems p
> In the National Basketball League there are five teams in the Pacific Division: Golden State, Los Angeles Clippers, Los Angeles Lakers, Phoenix, and Sacramento. How many different orders of finish are there for these five teams? (Assume that there are no
> The Consumer Financial Protection Bureau’s Consumer Response team hears directly from consumers about the challenges they face in the marketplace, brings their concerns to the attention of financial institutions, and assists in addressing their complaint
> The U.S. Department of Transportation maintains statistics for mishandled bags. In September 2016, the American Airlines rate of mishandled bags was 0.68 per 1,000 passengers. What is the probability that in the next 1,000 passengers, there will be a. n
> The U.S. Department of Transportation maintains statistics for mishandled bags per 1,000 airline passengers. In September 2016, Delta mishandled 1.35 bags per 1,000 passengers. What is the probability that in the next 1,000 passengers, Delta will have a
> Refer to Problem 5.22. How many cookies in a batch of 100 should the manager expect to discard if company policy requires that all chocolate-chip cookies sold have at least four chocolate-chip parts? Problem 5.22: The quality control manager of Marilyn’
> The quality control manager of Marilyn’s Cookies is inspecting a batch of chocolate-chip cookies that has just been baked. If the production process is in control, the mean number of chocolate-chip parts per cookie is 6.0. What is the probability that in
> In an effort to reduce the number of bottles that contain less than 1.90 liters, the bottler in Problem 6.34 sets the filling machine so that the mean is 2.02 liters. Under these circumstances, what are your answers in Problem 6.34 (a) through (e)? Prob
> The Air Travel Consumer Report, a monthly product of the Department of Transportation’s Office of Aviation Enforcement and Proceedings (OAEP), is designed to assist consumers with information on the quality of services provided by airli
> Assume that the number of airline customer service complaints filed with the Department of Transportation’s Office of Aviation Enforcement and Proceedings (OAEP) in one day is distributed as a Poisson variable. The mean number of airline customer service
> The annual NFL Super Bowl is the most widely watched sporting event in the United States each year. In recent years, there has been a great deal of interest in the ads that appear during the game. These ads vary in length, with most lasting 30 seconds or
> Assume a Poisson distribution with λ = 5.0. What is the probabiλity that a. X = 1? b. X < 1? c. X > 1? d. X≤ 1?
> Assume a Poisson distribution. a. If λ = 2.0, find P(X ≥ 2). b. If λ = 8.0, find P(X ≥ 3). c. If λ = 0.5, find P(X ≤ 1). d. If λ = 4.0, find P(X ≥ 1). e. If λ = 5.0, find P(X≤ 3).
> Assume a Poisson distribution. a. If λ = 2.5, find P(X = 2). b. If λ = 8.0, find P(X = 8). c. If λ = 0.5, find P(X = 1). d. If λ = 3.7, find P(X = 0).
> In Problem 7.28, suppose that the mean amount of juice squeezed is 5.0 ounces. a. What is the probability that the sample mean amount of juice will be at least 4.60 ounces? b. The probability is 70% that the sample mean amount of juice will be contained
> In Example 5.4 on page 209, you and two friends decided to go to Wendy’s. Now, suppose that instead you go to McDonald’s, which recently filled approximately 92.2% of the orders correctly. What is the probability that a. all three orders will be filled c
> In Example 5.4 on page 209, you and two friends decided to go to Wendy’s. Now, suppose that instead you go to Burger King, which recently filled approximately 90.5% of orders correctly. What is the probability that a. all three orders will be filled cor
> Past records indicate that the probability of online retail orders that turn out to be fraudulent is 0.08. Suppose that, on a given day, 20 online retail orders are placed. Assume that the number of online retail orders that turn out to be fraudulent is
> A manufacturing company regularly conducts quality control checks at specified periods on the products it manufactures. Historically, the failure rate for LED light bulbs that the company manufactures is 3%. Suppose a random sample of 10 LED light bulbs
> The following data represents the pounds per capita of fresh food and packaged food consumed in the United States, Japan, and Russia in a recent year. a. For the United States, Japan, and Russia, construct a bar chart, a pie or doughnut chart, and a P
> A student is taking a multiple-choice exam in which each question has four choices. Assume that the student has no knowledge of the correct answers to any of the questions. She has decided on a strategy in which she will place four balls (marked A, B, C,
> According to the Pew Research Center, 51% of American adults own tablets. Source: Data extracted from pewrsr.ch/2riDGV6. Using the binomial distribution, what is the probability that in the next six American adults surveyed, a. four will own a tablet?
> For a sample of n = 6, list the six Z values.
> The number of cars waiting in line at a car wash is distributed as follows: You can use a table of random numbers (Table E.1) to select samples from this distribution by assigning numbers as follows: 1. Start in the row corresponding to the day of th
> The increase or decrease in the price of a stock between the beginning and the end of a trading day is assumed to be an equally likely random event. What is the probability that a stock will show an increase in its closing price on five consecutive days?
> Determine the mean and standard deviation of the variable X in each of the following binomial distributions: a. n = 4 and π = 0.10 b. n = 4 and π = 0.40 c. n = 5 and π = 0.80 d. n = 3 and π = 0.50
> Determine the following: a. For n = 4 and π = 0.12, what is P(X = 0)? b. For n = 10 and π = 0.40, what is Π(X = 9)? c. For n = 10 and π = 0.50, what is Π(X = 8)? d. For n = 6 and π = 0.83, what is Π(X = 5)?
> A team is being formed that includes four different people. There are four different positions on the teams. How many different ways are there to assign the four people to the four positions?
> You plan to invest $1,000 in a corporate bond fund or in a common stock fund. The following table presents the annual return (per $1,000) of each of these investments under various economic conditions and the probability that each of those economic condi
> You are trying to develop a strategy for investing in two different stocks. The anticipated annual return for a $1,000 investment in each stock under four different economic conditions has the following probability distribution: Compute the a. expect
> Suppose that the owner of the restaurant in Problem 2.91 also wants to study the demand for dessert during the same time period. She decides that in addition to studying whether a dessert was ordered, she will also study the gender of the individual and
> The manager of the commercial mortgage department of a large bank has collected data during the past two years concerning the number of commercial mortgages approved per week. The results from these two years (104 weeks) are as follows: a. Compute the
> The number of arrivals per minute at a bank located in the central business district of a large city was recorded over a period of 200 minutes, with the following results: Arrivals Frequency 0 14 1 31 2 47 3 41 4 29 5 21 6 10 7 5 8 2 a. Compute the e
> In the carnival game Under-or-Over-Seven, a pair of fair dice is rolled once, and the resulting sum determines whether the player wins or loses his or her bet. For example, the player can bet $1 that the sum will be under 7—that is, 2, 3, 4, 5, or 6. For
> Show that for a sample of n = 39, the smallest and largest Z values are -1.96 and +1.96, and the middle (i.e., 20th) Z value is 0.00.
> Recently, a regional automobile dealership sent out fliers to perspective customers indicating that they had already won one of three different prizes: an automobile valued at $25,000, a $100 gas card, or a $5 Walmart shopping card. To claim his or her p
> The following table contains the probability Distribution for the number of traffic accidents daily in a small town: a. Compute the mean number of accidents per day. b. Compute the standard deviation. c. What is the probability that there will be at le
> Toss a coin 10 times and record the number of heads. If each student performs this experiment five times, a frequency distribution of the number of heads can be developed from the results of the entire class. Does this distribution seem to approximate th
> Given the following probability distributions: a. Compute the expected value for each distribution. b. Compute the standard deviation for each distribution. c. What is the probability that x will be at least 3 in Distribution A and Distribution B? d. C
> If there are 10 multiple-choice questions on an exam, each having three possible answers, how many different sequences of answers are there?
> You would like to ”build-your-own-burger” at a fast-food restaurant. There are five different breads, seven different cheeses, four different cold toppings, and five different sauces on the menu. If you want to include one choice from each of these ingre
> The owner of a restaurant that serves Continental-style entrées has the business objective of learning more about the patterns of patron demand during the Friday-to-Sunday weekend time period. Data were collected from 630 customers on the ty
> The editor of a textbook publishing company is trying to decide whether to publish a proposed business statistics textbook. Information on previous textbooks published indicates that 10% are huge successes, 20% are modest successes, 40% break-even, and 3
> The 2016 Global Information Security Workforce Study (GISWS) surveyed information security professionals regarding trends and issues affecting their profession and careers. In the study, women were asked about their impact on the security posture of thei
> Olive Construction Company is determining whether it should submit a bid for a new shopping center. In the past, Olive’s main competitor, Base Construction Company, has submitted bids 70% of the time. If Base Construction Company does not bid on a job, t
> Many manufacturing problems involve the matching of machine parts, such as shafts that fit into a valve hole. A particular design requires a shaft with a diameter of 22.000 mm, but shafts with diameters between 21.990 mm and 22.010 mm are acceptable. Sup
> Big Commerce launched a study to analyze modern, omnichannel consumer behavior. The data uncovers the details on how, when, where, and why Americans buy, educating the entire commerce industry on today’s consumer shopping preferences. Findings indicate t
> In Example 4.10, suppose that the probability that a medical diagnostic test will give a positive result if the disease is not present is reduced from 0.02 to 0.01. a. If the medical diagnostic test has given a positive result ( indicating that the dise
> If P(B) = 0.30, P(A|B) = 0.60, P(B’ ) = 0.70, and P(A|B’ ) = 0.50, find P(B|A).
> If P(B) = 0.05, P(A|B) = 0.80, P(B’ ) = 0.95, and P(A|B’ ) = 0.40, find P(B|A).
> The table of random numbers is an example of a uniform distribution because each digit is equally likely to occur. Starting in the row corresponding to the day of the month in which you were born, use a table of random numbers (Table E.1) to take one dig
> B2B marketers in North America were surveyed about content marketing usage, organization, and success. Content marketers were asked about how content marketing is structured within their organization and how they would describe their organizationâ&
> A box of nine iPhone 7 cellphones contains two red cellphones and seven black cellphones. a. If two cellphones are randomly selected from the box, without replacement (the first cellphone is not returned to the box after it is selected), what is the pro
> A particular brand of women’s jeans is available in seven different sizes, three different colors, and three different styles. How many different women’s jeans does the store manager need to order to have one pair of each type?
> A standard deck of cards is being used to play a game. There are four suits (hearts, diamonds, clubs, and spades), each having 13 faces (ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, jack, queen, and king), making a total of 52 cards. This complete deck is thoroughly
> In 42 of the 66 years from 1950 through 2016 (in 2011 there was virtually no change), the S&P 500 finished higher after the first five days of trading. In 37 out of 42 years, the S&P 500 finished higher for the year. Is a good first week a good o
> 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 warranty-related repair (yes or no) and the country in which the company
> Consider the following contingency table: What is the probability of event a. A? b. A? c. A and B? d. A or B? B B' A 10 20 A' 20 40
> 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
> Have the gains in student learning attributed to education technology justified colleges’ spending in this area? As part of Inside Higher Ed’s 2016 Survey of Faculty Attitudes on Technology, professors, and technology
> 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: a. If a respondent selected is a member of Generation X, what is the probability that he or she pays the
> How will marketers change their social media use in the near future? A survey by Social Media Examiner of B2B marketers (marketers that focus primarily on attracting businesses) and B2C marketers (marketers that primarily target consumers) was based on 1
> The stock market in Canada reported strong returns in 2016. The population of stocks earned a mean return of 17.5% in 2016. Source: Data extracted from The Wall Street Journal, December 31, 2016–Janaury 1, 2017, p. B6. Assume that the returns for stocks
> 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€
> 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 | B’? c. A’ | B’? 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
