Question: After watching a number of children playing

> To learn more about the size of withdrawals at a banking machine, the proprietor took a sample of 75 withdrawals and recorded the amounts. Determine the mean and standard deviation of these data, and describe what these two statistics tell you about the

> Variance is often used to measure the quality in production-line products. Suppose that a sample of steel rods that are supposed to be exactly 100 cm long is taken. The length of each is determined, and the results are recorded. Calculate the variance an

> Three men are trying to make the football team as punters. The coach had each of them punt the ball 50 times, and the distances were recorded. a. Compute the variance and standard deviation for each punter. b. What do these statistics tell you about the

> Many traffic experts argue that the most important factor in accidents is not the average speed of cars but the amount of variation. Suppose that the speeds of a sample of 200 cars were taken over a stretch of highway that has seen numerous accidents. Co

> a. List three methods of conducting a survey of people. b. Give an important advantage and disadvantage of each of the methods listed in part (a).

> A survey of Amazon.com shoppers reveals the following probability distribution of the number of books purchased per hit. a. What is the probability that an Amazon.com visitor will buy four books? b. What is the probability that an Amazon.com visitor wil

> There has been much media coverage of the high cost of medicinal drugs in the United States. One concern is the large variation from pharmacy to pharmacy. To investigate, a consumer advocacy group took a random sample of 100 pharmacies around the country

> A statistics practitioner determined that the mean and standard deviation of a data set were 120 and 30, respectively. What can you say about the proportions of observations that lie between each of the following intervals? a. 90 and 150 b. 60 and 180 c.

> A set of data whose histogram is extremely skewed yields a mean and standard deviation of 70 and 12, respectively. What is the minimum proportion of observations that a. are between 46 and 94? b. are between 34 and 106?

> Refer to Exercise 4.35. Approximately what proportion of observations a. are less than 46? b. are less than 58? c. are greater than 54? Data from Exercise 4.35: A set of data whose histogram is bell shaped yields a mean and standard deviation of 50 and 4

> A set of data whose histogram is bell shaped yields a mean and standard deviation of 50 and 4, respectively. Approximately what proportion of observations a. are between 46 and 54? b. are between 42 and 58? c. are between 38 and 62?

> Create a sample of five observations whose mean is 6 and whose standard deviation is 0.

> A friend calculates a variance and reports that it is –25.0. How do you know that he has made a calculation error?

> Refer to Exercise 4.31. Calculate the variance for each part. Was your answer in Exercise 4.31 correct? Data from Exercise 4.31: a. 17 b. 22 29 12 16 11 18 23 20 17 C. 24 37 6. 39 29

> Examine the three samples listed here. Without performing any calculations, indicate which sample has the largest amount of variation and which sample has the smallest amount of variation. Explain how you produced your answer. a. 17 b. 22 29 12 16 11

> Find the variance and standard deviation of the following sample. 0 −5 −3 6 4 −4 1 −5 0 3

> Refer to Exercise 7.22. a. Determine the probability distribution of the amount of money the arcade takes in per child. b. Use the probability distribution to calculate the mean and variance of the amount of money the arcade takes in. c. Compare the answ

> a. Briefly describe how you might design a study to investigate the relationship between smoking and lung cancer. b. Is your study in part (a) observational or experimental? Explain why.

> Determine the variance and standard deviation of the following sample. 12 6 22 21 23 13 15 17 21

> Calculate the variance of the following sample. 4 5 3 6 5 6 5 6

> Calculate the variance of the following sample. 9 3 7 4 1 7 5 4

> How much television were American adults watching in 2014 (TVHOURS)? Produce a histogram to help answer the question.

> How well were Americans doing financially in 2014. Draw a histogram of respondents’ incomes (RINCOME). Describe the shape.

> How educated were American adults in 2014? Draw a histogram to help provide a graphical answer (EDUC).

> Draw a histogram of the ages (AGE) of the respondents. What information do you draw from the histogram?

> The number of books shipped out daily by Amazon.com was recorded for 100 days. Draw a histogram and describe your findings.

> The volume of water used by each of a sample of 350 households was measured (in gallons) and recorded. Use a suitable graphical statistical method to summarize the data. What does the graph tell you?

> Refer to Exercise 7.23. Suppose that each game costs the player 25 cents. Use the laws of expected value and variance to determine the expected value and variance of the amount of money the arcade takes in. Data from Exercise 7.23: Determine the mean and

> Each of a sample of 240 tomatoes grown with a new type of fertilizer was weighed (in ounces) and recorded. Draw a histogram and describe your findings.

> A soft drink manufacturer has been supplying its cola drink in bottles to grocery stores and in cans to small convenience stores. The company is analyzing sales of this cola drink to determine which type of packaging is preferred by consumers. a. Is this

> Is it possible for a sample to yield better results than a census? Explain.

> Briefly describe three types of nonsampling error.

> a. Explain the difference between sampling error and nonsampling error. b. Which type of error in part (a) is more serious? Why?

> A statistics practitioner wants to estimate the mean age of children in his city. Unfortunately, he does not have a complete list of households. Describe a sampling plan that would be suitable for his purposes.

> The operations manager of a large plant with four departments wants to estimate the person-hours lost per month from accidents. Describe a sampling plan that would be suitable for estimating the plantwide loss and for comparing departments.

> A telemarketing firm has recorded the households that have purchased one or more of the company’s products. These number in the millions. The firm would like to conduct a survey of purchasers to acquire information about their attitude concerning the tim

> A large university campus has 60,000 students. The president of the students’ association wants to conduct a survey of the students to determine their views on an increase in the student activity fee. She would like to acquire information about all the s

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Rogers Communication (RCI.B) and Telus (T) Calculate the beta coefficient and the coefficient o

> Refer to Exercise 7.22. Determine the mean and variance of the number of games played. Data from Exercise 7.22: After watching a number of children playing games at a video arcade, a statistics practitioner estimated the following probability distributio

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Encana (ECA), Enbridge (ENB), and Suncor Energy (SU) Calculate the beta coefficient and the coe

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Bank of Montreal (BMO), Bank of Nova Scotia (BNS), and Royal Bank of Canada (RY) Calculate the

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Telus (T) Determine the average beta coefficient for the stocks in the listed portfolio. Calcul

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Enbridge (ENB) Calculate the beta coefficient and the coefficient of determination for the list

> Monthly returns for the Toronto Stock Exchange Index and the following selected stocks on the Toronto Stock Exchange were recorded for the years 2011 to 2015: Barrick Gold (ABX) Calculate the beta coefficient and the coefficient of determination for the

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Merck (MRK), Pfiz

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Travelers (TRV),

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Boeing (BA), Cate

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Visa (V) For the

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Nike (NKE) For th

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. Home Depot (HD) F

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. General Electric

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. American Express

> We have recorded the monthly returns for the S&P 500 index and the following 26 of the 30 Dow Jones Industrials stocks listed on the New York Stock Exchange (The other four are on the NASDAQ.) for the period January 2011– December 2015. McDonald’s (MCD)

> Repeat Exercise 4.109 for the 2012–2013 National Hockey league season. Data from Exercise 4.109: We recorded the number of wins, team payrolls, home attendance, and away attendance for the 2015–2016 National Hockey League season. a. Estimate the marginal

> A statistics practitioner would like to conduct a survey to ask people their views on a proposed new shopping mall in their community. According to the latest census, there are 500 households in the community. The statistician has numbered each household

> We recorded the number of wins, team payrolls, home attendance, and away attendance for the 2015–2016 National Hockey League season. a. Estimate the marginal cost of winning one more game. b. Estimate the marginal number of tickets sold for each addition

> Repeat Exercise 4.107 for the 2012–2013 National Football League season Data from Exercise 4.107: The number of wins, team payrolls, home attendance, and away attendance were recorded for the 2015–2016 National Football League season. a. Estimate the mar

> The number of wins, team payrolls, home attendance, and away attendance were recorded for the 2015–2016 National Football League season. a. Estimate the marginal cost of winning one more game. b. Estimate the marginal number of tickets sold for each addi

> Repeat Exercise 4.105 for the 2012–2013 National Basketball Association season. Data from Exercise 4.105: The number of wins, team payrolls, home attendance, and away attendance were recorded for the 2015–2016 National Basketball Association season. a. C

> Refer to Exercise 7.20. If the pizzeria makes a profit of $3 per pizza, determine the mean and variance of the profits per student. Data from Exercise 7.20: The number of pizzas delivered to university students each month is a random variable with the fo

> The number of wins, team payrolls, home attendance, and away attendance were recorded for the 2015–2016 National Basketball Association season. a. Conduct an analysis to determine the marginal cost of winning one more game. b. Analyze the relationship be

> Repeat Exercise 4.102 for the 2012 baseball season. Data from Exercise 4.102: The practitioner also recorded the average away attendance for each team in the 2015 season. Since visiting teams take a share of the gate, owners should be interested in this

> Repeat Exercise 4.101 for the 2012 baseball season. Data from Exercise 4.101: The chapter-opening example showed that there is a very weak linear relationship between a baseball teams’ payroll and the number of wins. This raises the question: Are success

> Refer to Exercise 4.101. The practitioner also recorded the average away attendance for each team in the 2015 season. Since visiting teams take a share of the gate, owners should be interested in this analysis. a. Are visiting team attendance related to

> The chapter-opening example showed that there is a very weak linear relationship between a baseball teams’ payroll and the number of wins. This raises the question: Are success on the field and attendance related? If the answer is no, then profit-driven

> The U.S.–Canada exchange rate has fluctuated over the past 45 years. Can any single commodity explain these fluctuations? Is it oil, for example? Canada sells a lot of oil to the United States. It may be lumber or gold. A statistician set out to investig

> Suppose your statistics professor distributes a questionnaire about the course. One of the questions asks, “Would you recommend this course to a friend?” Can the professor use the results to infer something about all statistics courses? Explain.

> Briefly describe the difference between observational and experimental data.

> An investment you made 5 years ago has realized the following rates of return. a. Compute the mean and median of the rates of return. b. Compute the geometric mean. c. Which one of the three statistics computed in parts (a) and (b) best describes the re

> The following returns were realized on an investment over a 5-year period. a. Compute the mean and median of the returns. b. Compute the geometric mean. c. Which one of the three statistics computed in parts (a) and (b) best describes the return over th

> The number of pizzas delivered to university students each month is a random variable with the following probability distribution. a. Find the probability that a student has received delivery of two or more pizzas this month. b. Determine the mean and v

> What is the geometric mean of the following rates of return? .50 .30 −.50 −.25

> Compute the geometric mean of the following rates of return. .25 −.10 .50

> The professors at Wilfrid Laurier University are required to submit their final exams to the registrar’s office 10 days before the end of the semester. The exam coordinator sampled 20 professors and recorded the number of days before th

> The midterm test for a statistics course has a time limit of 1 hour. However, like most statistics exams this one was quite easy. To assess how easy, the professor recorded the amount of time taken by a sample of nine students to hand in their test paper

> A random sample of 12 joggers was asked to keep track and report the number of miles they ran last week. The responses are a. Compute the three statistics that measure central location. b. Briefly describe what each statistic tells you. 5.5 7.2 1.6

> The number of sick days due to colds and flu last year was recorded by a sample of 15 adults. The data are Compute the mean, median, and mode. 6 5 9 2 0 12 7 0 3 15 3 8 10 5

> The number of copies made by an office copier was recorded for each of the past 75 days. Graph the data using a suitable technique. Describe what the graph tells you.

> A random sample of households was surveyed. Each was asked how old their refrigerators were (in months). a. Compute the mean and median of these data. b. What have you learned about this data set from the statistics?

> In an effort to slow drivers, traffic engineers painted a solid line 3 feet from the curb over the entire length of a road and filled the space with diagonal lines. The lines made the road look narrower. A sample of car speeds was taken after the lines w

> In the United States, banks and financial institutions often require buyers to pay fees in order to arrange mortgages. In a survey conducted by the U.S. Federal Housing Finance Board, 400 buyers of new houses who received a mortgage from a bank were aske

> We are given the following probability distribution. a. Calculate the mean, variance, and standard deviation. b. Suppose that Y = 3X + 2. For each value of X, determine the value of Y . What is the probability distribution of Y ? c. Calculate the mean,

> According to a recent National Household Survey (NHS), roughly 15.4 million Canadians commuted to work. Overall, about four out of five Canadian commuters used private vehicles. Specifically, 74.0% of commuters, or 11.4 million workers, drove a vehicle t

> The amount of time spent commuting by residents of Washington D.C. was recorded for a sample of 235 commuters. a. Compute the mean and median. b. What do the mean and median tell you about this data set?

> The starting salaries of a sample of 300 recent Bachelor of Business Administration graduates were recorded. Calculate the mean and median. Interpret the meaning of each statistic.

> An auction house conducts an auction once every week listing items such as jewelry, furniture, art, coins, and many others. The number of bidders from each of the auctions over the last 3 years was recorded. Determine the mean and median of the weekly nu

> Suppose that you bought a stock 6 years ago at $12 . The stock’s price at the end of each year is shown here. a. Compute the rate of return for each year. b. Compute the mean and median of the rates of return. c. Compute the geometric

> An investment of $1,000 you made 4 years ago was worth $1,200 after the first year, $1,200 after the second year, $1,500 after the third year, and $2,000 today. a. Compute the annual rates of return. b. Compute the mean and median of the rates of return.

> A sample of 12 people was asked how much change they had in their pockets and wallets. The responses (in cents) are Determine the mean, median, and mode for these data. 52 25 15 0 104 44 60 30 33 81 40

> The total light beer sales in the United States is approximately 3 million gallons annually. With this large a market, breweries often need to know more about who is buying their product. The marketing manager of a major brewery wanted to analyze the lig

> An increasing number of statistics courses use a computer and software rather than manual calculations. A survey of statistics instructors asked each to report the software his or her course uses. The responses are as follows: 1. Excel 2. Minitab 3. SAS

> Many business and economics courses require the use of computer, so students often must buy their own computers. A survey asks students to identify which computer brand they have purchased. The responses are as follows: 1. HP 2. Lenovo 3. Dell 4. Other a

> The random variable X has the following distribution. a. Find the mean and variance for the probability distribution below. b. Determine the probability distribution of Y where Y = 5X. c. Use the probability distribution in part (b) to compute the mean

> Who applies to MBA programs? To help determine the background of the applicants, a sample of 230 applicants to a university’s business school was asked to report their undergraduate degree. The degrees were recorded using these codes. 1. BA 2. BBA 3. B.E

> For each of the following examples of data, determine the type. a. The weekly closing price of the stock of Amazon.com b. The month of highest vacancy rate at a La Quinta motel c. The size of soft drink (small, medium, or large) ordered by a sample of Mc

> Subway train riders frequently pass the time by reading a newspaper. New York City has a subway and four newspapers. A sample of 360 subway riders who regularly read a newspaper was asked to identify that newspaper. The responses are as follows: 1. New

> A survey asked 392 homeowners which area of the home they would most like to renovate. The responses and frequencies are shown next. Use a graphical technique to present these results. Briefly summarize your findings. Area

> Where do consumers get information about cars? A sample of recent car buyers was asked to identify the most useful source of information about the cars they purchased. The responses are as follows: 1. Consumer guide 2. Dealership 3. Word of mouth 4. Int

> What are the most important characteristics of colleges and universities? This question was asked of a sample of college-bound high school seniors. The responses are as follows: 1. Location 2. Majors 3. Academic reputation 4. Career focus 5. Community 6

> Governments in both Canada and the United States have considered passing legislation that increases the minimum hourly wage to $15. The current (as of October 2015) minimum hourly wage in each Canadian province and the percentage of employees earning the