Questions and Answers of Business Statistics A First Course

Explain how to construct(a) A cause-and-effect diagram.(b) A defect concentration diagram.
Explain the purpose behind constructing(a) A cause-and-effect diagram.(b) A defect concentration diagram.
Give an example of a conditional probability that would be of interest to you?
A grocer has a contract with a produce wholesaler that specifies that the wholesaler will supply the grocer with grapefruit that weigh at least .75 pounds each. In order to monitor the grapefruit
Explain how the natural tolerance limits compare to the specification limits whena. A process is capable of meeting specifications.b. A process is not capable of meeting specifications.
A company packages a bulk product in bags with a 50-pound label weight. During a typical day’s operation of the fill process, 22 subgroups of five bag fills are observed. Using the observed data,
Write an essay comparing the management philosophy that Dr. Deming advocated in his 14 points to the management styles you have been exposed to in your personal work experiences. Do you think Dr.
Describe several common causes and several assignable causes that might result in variation of the given quality characteristic.a. Process: getting ready for school or work in the morning. Quality
What are the advantages of using a stem-and-leaf display?
Find an example of a pie chart or bar chart in a newspaper or magazine. Copy it, and hand it in with a written analysis of the information conveyed by the chart.
Draw a scatter plot of y versus x in which there is little or no linear relationship between y and x.
Draw a scatter plot of y versus x in which y increases in a linear fashion as x increases.
Draw a scatter plot of y versus x in which y decreases in a linear fashion as x increases.
Define a population. Give an example of a population.
The following table gives the value of the Dow Jones Industrial Average (DJIA), NASDAQ, and the S&P 500 on the first day of trading for the years 2008 through 2010.a. For each stock index,
Find an example of a misleading use of statistics in a newspaper, magazine, corporate annual report, or other source. Then explain why your example is misleading.
Table 2.25 presents data concerning the largest U.S. charities as rated on the Forbes.com website on June 14, 2011.a. Construct a percent frequency histogram of each of(1) the charities’ private
The price/earnings ratio of a firm is a multiplier applied to a firm’s earnings per share (EPS) to determine the value of the firm’s common stock. For instance, if a firm’s earnings per share
a. If df = 8, find the chi-square pointsb. If df = 16, find the chi-square points X025, X01, and Xoos
Suppose that n = 10 and s2 = 9. Assume normality. a. Compute a 95 percent confidence interval for σ2.b. Test the null hypothesis H0: σ2 = 15 versus Ha: σ2 < 15 at the .05 level of
Suppose that n = 20 and s2 = 25Assume normality.a. Compute a 99 percent confidence interval for σ2b. Test the null hypothesis Ho: σ2 = 35 Ha : σ2 ≠ 35 at the .01 level of significance.
Suppose that n = 25 and s2 = 49. Assume normality.a. Compute a 98 percent confidence interval for σ2.b. Compute a 98 percent confidence interval for σ.c. Test the null hypothesis Ho: σ2 = 25
Hoping to reduce the variability of the final exam scores in his business statistics classes, an instructor at Miami University in Oxford, Ohio, developed a new set of PowerPoint presentations to use
Explain what population is described by the sampling distribution of s21/s22.
The stopping distances of a random sample of n1 = 16 Fire-Hawk compact cars have a mean of x̅1 = 57.2 feet and a standard deviation of s1 = 4.81 feet. The stopping distances of a random sample of n2
A company is studying the productivity of a machine that produces an automobile part. The times (in seconds) needed to produce 100 parts for each of eight test production runs were: 40.77, 36.38,
In Exercise 10.11, we used the unequal variances procedure to compare population means. The sample standard deviations involved in the comparison were s1 = 68 and s2 = 22. Each sample size was 10.a.
We usually take action on the basis of having rejected the null hypothesis. When we do this, we know the chances that the action has been taken erroneously because we have prespecified a, the
Prenumbered sales invoices are kept in a sales journal. The invoices are numbered from 0001 to 5000.a. Beginning in row 16, column 01, and proceeding horizontally in a table of random numbers (Table
The financial services call center in Problem 2.20 also monitors call duration, the amount of time spent speaking to customers on the phone. The file CallDuration contains the following data for
The time it takes to download a video from the Internet is measured. Explain why the download time is a continuous numerical variable.
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)
The file Protein contains calorie and cholesterol information for popular protein foods (fresh red meats, poultry, and fish).a. Construct frequency and percentage distributions for the number of
What is meant by the property of variation?
What is meant by the property of shape?
In 43 of the 67 years from 1950 through 2017 (in 2011 there was virtually no change), the S&P 500 finished higher after the first five days of trading. In 38 out of 43 years, the S&P 500
An insurance company has the business objective of reducing the amount of time it takes to approve applications for life insurance. The approval process consists of underwriting, which includes a
If P(A and B) = 0.4 and P(B) = 0.8, find P(A|B).
In the Short Takes 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
P(A) = 0.3, P(B) = 0.4, and P(A and B) = 0.2, are A and B independent?
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
The following table contains the probability distribution for the number of traffic accidents per day in a small town:a. Calculate the mean number of accidents per day.b. Calculate the standard
If P(B) = 0.05, P(A|B) = 0.80, P(B′) = 0.95, and P(A|B′) = 0.40, find P(B|A).
If P(B) = 0.30, P(A|B) = 0.60, P(B′) = 0.70, and P(A|B′) = 0.50, find P(B|A).
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
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
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
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
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
In Example 5.4 shown below 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
In Example 5.4 shown below 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
Assume a Poisson distribution with l = 5.0. What is the probability thata. X = 1?b. X < 1?c. X > 1?d. X ≤ 1?
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
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
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
The U.S. Department of Transportation maintains statistics for mishandled bags per 1,000 airline passengers. In January 2017, Delta mishandled 3.08 bags per 1,000 passengers. What is the probability
The U.S. Department of Transportation maintains statistics for mishandled bags. In January 2017, the American Airlines rate of mishandled bags was 3.64 per 1,000 passengers. What is the probability
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
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
What is the meaning of the expected value of a variable?
In 2016, the per capita consumption of bottled water in the United States was reported to be 39.3 gallons. Assume that the per capita consumption of bottled water in the United States is
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
Millennials spent a mean of $2,921 annually dining in 2016. Assume that the amount spent on annual dining is normally distributed and that the standard deviation is $12.a. What is the probability
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
A Nielsen study indicates that 18- to 34-year olds spend a mean of 116 minutes watching video on their smartphones per week during the fourth quarter of 2016. Assume that the amount of time watching
In 2016, the per capita consumption of soft drinks in the United States was reported to be 642 eight-ounce servings. Assume that the per capita consumption of soft drinks in the United States is
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
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.
The file Property Taxes contains the property taxes on a $176K home for the 50 states and the District of Columbia. Decide whether the data appear to be approximately normally distributed bya.
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:Decide whether the data appear to be
Thirty companies comprise the DJIA. How big are these companies? One common method for measuring the size of a company is to use its market capitalization, which is computed by multiplying the number
The file CD Rate contains the yields for a one-year certificate of deposit (CD) and a five-year CD for 52 banks listed for West Palm Beach, Florida on December 29, 2017.For each type of investment,
How do you find the X value that corresponds to a given percentile of the normal distribution?
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
In an effort to reduce the number of bottles that contain less than 1.90 liters, the bottler in Problem 6.30 sets the filling machine so that the mean is 2.02 liters. Under these circumstances, what
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
The major stock market indexes had strong results in 2017. The mean one-year return for stocks in the S&P 500, a group of 500 very large companies, was +10.42%. The mean one-year return for the
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
According to the same Glassdoor source mentioned in Problem 6.36, the mean monthly pay for interns at Facebook is $6,589. Suppose that the intern monthly pay is normally distributed, with a standard
Given a normal distribution with μ = 100 and σ = 10, if you select a sample of n = 25, what is the probability that X̅ isa. Less than 95?b. Between 95 and 97.5?c. Above 102.2?d. There is a 65%
Given a normal distribution with μ = 50 and σ = 5, if you select a sample of n = 100, what is the probability that X̅ isa. Less than 47?b. Between 47 and 49.5?c. Above 51.1?d. There is a 35%
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
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
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
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
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.
The following data represent the responses (Y for yes and N for no) from a sample of 40 college students to the question “Do you currently own shares in any stocks?”a. Determine the sample
In a random sample of 64 people, 48 are classified as “successful.”a. Determine the sample proportion, p, of “successful” people.b. If the population proportion is 0.70, determine the
A random sample of 50 households was selected for a phone (landline and cellphone) survey. The key question asked was, “Do you or any member of your household own an Apple product (iPhone, iPod,
What do millennials around the world want in a job? A Deloitte survey of millennials on work-life challenges found that millennials are looking for stability in an uncertain world, with 65% of
The goal of corporate sustainability is to manage the environmental, economic, and social effects of a corporation’s operations so it is profitable over the long-term while acting in a responsible
According to the MSCI 2016 Survey of Women on Boards, women hold 20% of director seats on U.S. corporate boards. This study also reports that 34% of U.S. companies have three or more female board
The topic of global warming increasingly appears in the news. It has the potential to impact companies’ operations through changes in governmental regulations, new reporting requirements, necessary
Original digital video is defined as professionally produced video only for ad-supported online distribution and viewing (not TV). An IAB study on the state of original digital video showed that
What is the difference between a population distribution and a sampling distribution?
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
Why does widening the confidence interval (thereby making it less precise) increase confidence for a given sample size, n?
What is meant by the power of a test?
What is meant by a p-value?
What is the six-step critical value approach to hypothesis testing?

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