Question: You have begun a quality improvement campaign

> It is currently difficult to hire in the technology sector. Your company believes that the chances of successfully hiringthisyearare0.13.Giventhatyourcompanyissuccessful in hiring, the chances of finishing the project on time are 0.78, but if hiring is n

> A repair shop has two technicians with different levels of training. The technician with advanced training is able to fix problems 92% of the time, while the other has a success rate of 80%. Assume you have a 30% chance of obtaining the technician with a

> The human resources department of a company is considering using a screening test as part of the hiring process for new employees and is analyzing the results of a recent study. It was found that 63% of applicants score high on the test, but only 79% of

> Your company maintains a database within formation on your customers, and you are interested in analyzing patterns observed over the past quarter. In particular, 23% of customers in the database placed new orders within this period. However, for those cu

> Two events are mutually exclusive, one with probability 0.38 and the other with probability 0.54. a. Find the conditional probability that the first event happens given that the second event happens. b. Find the probability of the union of these two even

> Your firm has classified orders as either large or small in dollar amounts and as either light or heavy in shipping weight. In the recent past, 28% of orders have been large dollar amounts, 13% of orders have been heavy, and 10% of orders have been large

> The probability of getting a big order currently under negotiation is 0.32. The probability of losing money this quarter is 0.54. a. Assume that these are mutually exclusive events. Find the probability of getting the order or losing money this quarter.

> As a stock market analyst for a major brokerage house, you are responsible for knowing everything about the automotive companies. In particular, Ford is scheduled to release its net earnings for the past quarter soon, and you do not know what that number

> Based on a demand analysis forecast, a factory plans to produce 80,000 video game cartridges this quarter, on average, with an estimated uncertainty of 25,000 cartridges as the standard deviation. The fixed costs for this equipment are $72,000 per quarte

> Break down the annual salaries into three groups according to training level (A, B, or C). a.* Draw box plots to compare these three groups. Comment on what you see. b.* Find the average for each training level, and comment. c.* Find the between-sample a

> Repeat problem 6 with the extreme outlier omitted, and write a paragraph comparing the results with and without the outlier. Data from problem 6: Consider the number of executives for all Seattle corporations with 500 or more employees 19: 12, 15, 5, 1

> Consider the number of executives for all Seattle corporations with 500 or more employees 19: 12, 15, 5, 16, 7, 18, 15, 12, 4, 3, 22, 4, 12, 4, 6, 8, 4, 5, 6, 4, 22, 10, 11, 4, 7, 6, 10, 10, 7, 8, 26, 9, 11, 41, 4, 16, 10, 11, 12, 8, 5, 9, 18, 6, 5 a. Fi

> Consider the assets of stock mutual funds, as shown in Table 5.5.3. Answer the parts of the previous problem using the column of assets instead of the rates of return. Table 5.5.3: TABLE 5.5.3 Natural Resources Mutual Funds: Rates of Return (12 mo

> Using the data from Table 2.6.7 of Chapter 2 for the 30 Dow Jones Industrial companies percent changes since January 2015: a. Find the standard deviation of the percent change. b. Find the range of the percent change. Table 2.6.7: TABLE 2.6.7 Closi

> How much variability is the rein loan fees for home mortgages? Find and interpret the standard deviation, range, and coefficient of variation for the data in Table 4.3.8 of Chapter 4. Table 4.3.8: TABLE 4.3.8 Home Mortgage Loan Fees for Dallas, TX

> Use the data set from problem 21 of Chapter 3 on poor quality in the production of electric motors. a. Find the standard deviation and range to summarize the typical batch-to-batch variability in quality of production. b. Remove the two outliers and re c

> Using the data from Table 3.8.4 in Chapter 3 for the market values of the portfolio investments of College Retirement Equities Growth Fund (CREF) in the media sector: a. Find the standard deviation of portfolio value for these firms’ st

> For the municipal bond yields of Table 3.8.1 in Chapter 3: a. Find the standard deviation of the yield. b. Find the range. c. Find the coefficient of variation. d. Use these summaries to describe the extent of variability among these yields. Table 3.8.1

> For the international goods and services tax data of Table 5.5.10, which shows these taxes as a percentage of GDP (gross domestic product, a measure of total national economic activity) and as a percentage of revenue: a. Draw a box plot for each variable

> Different countries have different taxation strategies: Some tax income more heavily than others, while others concentrate on goods and services taxes. Consider the relative size of goods and services taxes for selected countries’ inter

> Write a three- to five-page report summarizing the relationship between gender and salary for these employees. Be sure to discuss the results of the following statistical analyses: (a) a two-sample t-test of male salaries against female salaries and (b)

> Consider the return on equity, expressed like an interest rate in percentage points per year, for a sample of companies: 5.5, 10.6, 19.0, 24.5, 6.6, 26.8, 6.2, 2.4, 28.3, 2.3 a. Find the average and standard deviation of the return on equity. b. Interpre

> Samples from the mine show the following percentages of gold: 1.1, 0.3, 1.5, 0.4, 0.8, 2.2, 0.7, 1.4, 0.2, 4.5, 0.2, 0.8 a. Compute and interpret the sample standard deviation. b. Compute and interpret the coefficient of variation. c. Which data value ha

> Here are first-year sales (in thousands) for some recent new product introductions that are similar to one you are considering. 10, 12, 16, 47, 39, 22, 10, 29 a. Find the average and standard deviation. Interpret the standard deviation. b. After you went

> Consider the following productivity measures (on a scale from 0 to 100) for a population of employees: 85.7, 78.1, 69.1, 73.3, 86.8, 72.4, 67.5, 76.8, 80.2, 70.0 a. Find the average productivity. b. Find and interpret the standard deviation of productivi

> Consider the annualized stock return over the decade from 2000 to 2010, July to July, expressed as an annual interest rate in percentage points per year, for major pharmaceutical companies as shown in Table 5.5.2. For these top firms in this industry gro

> Here are rates of return for a sample of recent on-site service contracts: 78.9%, 22.5%, 5.2%, 997.3%, 20.7%, 13.5%, 429.7%, 88.4%, 52.1%, 960.1%, 38.8%, 70.9%, 73.3%, 47.0%, 1.5%, 23.9%, 35.6%, 62.0%, 75.7%, 14.0%, 81.2%, 46.9%, 135.1%, 34.6%, 85.3%, 73

> Consider the variability in traffic congestion in Table 5.5.5 for northeastern and for southwestern cities. a. Compare population variability of these two groups of cities. In particular, which group shows more variability in congestion from city to city

> We have all been stopped by traffic at times and have had to sit there while freeway traffic has slowed to a crawl. If you have someone with you (or some good music), the experience may be easier to put up with, but what does traffic congestion cost soci

> You have been trying to control the weight of a chocolate and peanut butter candy bar by intervening in the production process. Table 5.5.4 shows the weights of two representative samples of candy bars from the day’s production, one tak

> Let us compare the distribution of the number of lifetime gifts of those who made a current donation to that of those who did not. We will use two data sets, each indicating the number of gifts (life time gifts, previous to this mailing) given by the 20,

> Consider the prediction of annual salary from age alone (as compared to exercise 1, where experience was also used as an X variable). a. Find the regression equation to predict annual salary from age. b. Using results from part a of exercise 1 and this e

> Consider the number of gifts (lifetime gifts, previous to this mailing) given by the 20,000 people represented in the donations database (on the companion site). a. Find the average and standard deviation. b. Draw a histogram for this data set. Indicate

> Planning to start an advertising agency? Table 5.5.1 reports the size of account budgets, within the Internet category, for selected firms. a. Find the average budget size. b. Find the standard deviation of budget sizes, viewing these firms as a sample o

> The beta of a firm’s stock indicates the degree to which changes in stock price track changes in the stock market as a whole and is interpreted as the market risk of the portfolio. A beta of 1.0 indicates that, on average, the stock rises (or falls) the

> Consider the profits of health care companies in the Fortune 500, as shown in Table 4.3.3 a. Draw a histogram of this data set, and briefly describe the shape of the distribution. b. Find the profit of the average firm. c. Find the median profit level. d

> A wine store carries 86 types of wine produced in 2007, 125 types from 2008, 73 from 2009, and 22 from 2010. Identify the types of wine as the elementary units for analysis. a. Find the mode of the year of production. What does this tell you? b. Find the

> Consider the running times of selected films from a video library as shown in Table 4.3.10. a. Find the average running time. b. Find the median running time. c. Which is larger, the average or the median? Based on your answer, do you expect to find stro

> Using the data from Table 3.8.4 in Chapter 3, for the market values of the portfolio investments of College Retirement Equities Growth Fund in the media sector: a. Find the average market value for these firms’ stock in CREFâ&#128

> For the yields of municipal bonds (Table 3.8.1 in Chapter 3): a. Find the average yield. b. Find the median yield. c. Find the quartiles. d. Find the five-number summary. e. Draw a box plot of these yields. f. Identify the outliers, if any, and draw a de

> Consider the percentage change in the value of the dollar with respect to Asia-Pacific currencies, year-to-date as of mid-October 2015 (Table 4.3.9). a. Find the average percentage change in the value of the dollar, averaging over all of these countries.

> Consider the monthly sales of 17selectedsalesrepresentatives (in thousands of dollars): 23, 14, 26, 22, 28, 21, 34, 25, 32, 32, 24, 34, 22, 25, 22, 17, 20 a. Find the average and median. b. Draw the box plot.

> Consider the prediction of annual salary from age and experience. a. Find and interpret the regression equation and regression coefficients. b. Find and interpret the standard error of estimate. c. Find and interpret the coefficient of determination. d.

> Consider the following list of your products’ share of 20 major metropolitan areas: 0.7%, 20.8%, 2.3%, 7.7%, 5.6%, 4.2%, 0.8%, 8.4%, 5.2%, 17.2%, 2.7%, 1.4%, 1.7%, 26.7%, 4.6%, 15.6%, 2.8%, 21.6%, 13.3%, 0.5% a. Find the average and the median. b. Draw a

> Consider the strength of cotton yarn used in a weaving factory, in pounds of force at breakage, measured from a sample of yarn from the supplies room: 117, 135, 94, 79, 90, 85, 173, 102, 78, 85, 100, 205, 93, 93, 177, 148, 107 a. Find the average breakin

> Consider the loan fees charged for granting home mortgages, as shown in Table 4.3.8, for Dallas TX, 30-year fixed rate for home purchase, with credit Score 740+, and with 20% down payment. These are given as a percentage of the loan amount and are one-ti

> Table 4.3.7 shows percent increases from the offer price of initial public stock offerings, as most of these newly traded companies increased in value, whereas some of them lost money. a. Draw a cumulative distribution function for this dataset. b. Find

> Consider the revenues (in $ millions) for the top 12 companies in the Fortune 500 (from http://fortune.com/ fortune500/ accessed October 20, 2015.), as shown in Table 4.3.6. a. Find the five-number summary. b. Draw a box plot. Table 4.3.6: TABLE 4.

> Consider the percent change in housing values over a five-year period for regions of the United States, as shown in Table 4.3.5. a. Find the mean and median percent change in housing values. b. Find the five-number summary for this data set. c. Draw a bo

> Consider the 20,000 people in the donations database (on the companion site). a. Construct box plots to compare median household income and per capita income (these specify two columns in the database) by putting the two box plots on the same scale. b. D

> Using the data from Table 2.6.8 of Chapter 2 for daily values for the Dow Jones Industrial Average: a. Find the mean net change. b. Find the median net change. c. Find the five-number summary for net change. d. Draw a box plot for net change. e. Find the

> Using the data from Table 2.6.7 of Chapter 2 for the 30 Dow Jones Industrial companies percent changes since January 2015: a. Find the mean percent change. b. Find the median percent change. c. Find the five-number summary for percent change. d. Draw the

> Consider predicting annual salary from age, experience, and an interaction term. a. Create a new variable, “interaction,” by multiplying age by experience for each employee. b. Find the regression equation to predict annual salary from age, experience, a

> Many marketers assumed that consumers would go for reduced-calorie foods in a big way. While these “light” foods caught on to some extent, they hadn’t yet sold in the large quantities their producers

> Use the data set from problem 21 of Chapter 3 on poor quality in the production of electric motors. a. Find the average and median to summarize the typical level of problems with quality of production. b. Remove the two outliers, and re compute the avera

> Consider the 20,000 median household income values in the donations database (available on the companion site). These represent the median household income for the neighborhood of each potential donor in the database. a. Construct a cumulative distributi

> Consider the data on CEO compensation in computer programming, data processing, and other related services firms from Table 3.8.7 of Chapter 3. a. Draw a detailed box plot. b. Find the 10th percentile of compensation. Table 3.8.7: TABLE 3.8.7 CEOo

> Consider the costs charged for treatment of heart failure and shock by hospitals in the Puget Sound area, using the data from Table 3.8.6 of Chapter 3. a. Summarize the costs. b. Draw a box plot. c. Draw a cumulative distribution function. d. If your hos

> Recall in the example on CEO compensation by prepackaged software companies from Chapter 3 that we identified an outlier (Lawrence J. Ellison of Oracle Corp, with compensation of $56.81 million). a. Draw a detailed box plot for this dataset. How many out

> Consider the following list of your product’s market share of 20 major metropolitan areas: 0.7%, 20.8%, 2.3%, 7.7%, 5.6%, 4.2%, 0.8%, 8.4%, 5.2%, 17.2%, 2.7%, 1.4%, 1.7%, 26.7%, 4.6%, 15.6%, 2.8%, 21.6%, 13.3%, 0.5%. a. Construct an appropriate histogram

> Consider the 20,000 median household income values in the donations database (available at the companion site). These represent the median household income for the neighborhood of each potential donor in the database. a. Construct a histogram. b. Describ

> Using the data from Table 2.8 of Chapter 2 for daily values for the Dow Jones Industrial Average: a. Construct a histogram for net change during September 2015. b. Describe the shape of the distribution. c. Construct a histogram for percent change during

> Using the data from Table 2.7 of Chapter 2 for the 30 Dow Jones Industrial companies: a. Construct a histogram for percent change since January 2015. b. Describe the shape of the distribution. Table 2.7: TABLE 2.6.7 Closing Price and Year-to-Date P

> Now examine the effect of training level on annual salary, with and without adjusting for age and experience. a. Find the average annual salary for each of the three training levels and compare them. b. Find the multiple regression equation to predict an

> Consider the following list of prices (in dollars) charged by different pharmacies for 12 60-mg tablets of the prescription drug Tylenol No. 4 with codeine: 17 6.75, 12.19, 9.09, 9.09, 13.09, 13.45, 7.89, 12.00, 10.49, 15.30, 13.29. a. Construct a histog

> Consider the percentage change in the value of the dollar with respect to Asia-Pacific currencies over approximately three quarters from start of 2015 through mid October (Table 3.8.13). a. Construct an appropriate histogram of this data set. b. Describe

> As part of your firm’s loyalty system, there is a database with information about customers who have joined, including the size of their immediate family, the number of cars they own, and their income. a. Based only on this information, does this databas

> Draw a histogram for the following list of prices charged by different stores for a box of envelopes (in dollars) and describe the distribution shape: 4.40, 4.20, 4.55, 4.45, 4.40, 4.10, 4.10, 3.80, 3.80, 4.30, 4.90, 4.20, 4.05.

> Consider the order size of recent customers (in thousands of dollars): 31, 14, 10, 3, 17, 5, 1, 17, 1, 2, 7, 12, 28, 4, 4, 10, 4, 3, 9, 28, 4, 3. a. Construct a histogram for this data set. b. Describe the distribution shape.

> Consider the salaries (in thousands of dollars) of a group of business executives: 177, 54, 98, 57, 209, 56, 45, 98, 58, 90, 116, 42, 142, 152, 85, 53, 52, 85, 72, 45, 168, 47, 93, 49, 79, 145, 149, 60, 58 a. Construct a histogram of this data set. b. De

> Draw a histogram of the market values of your main competitors (in millions of dollars) and describe the distribution shape: 3.7, 28.3, 10.6, 0.1, 9.8, 6.2, 19.7, 23.8, 17.8, 7.8, 10.8, 10.9, 5.1, 4.1, 2.0, 24.2, 9.0, 3.1, 1.6, 3.7, 27.0, 1.2, 45.1, 20.4

> Draw a histogram of interest rates offered by banks on certificates of deposit and describe the distribution shape: 9.9%, 9.5%, 10.3%, 9.3%, 10.4%, 10.7%, 9.1%, 10.0%, 8.8%, 9.7%, 9.9%, 10.3%, 9.8%, 9.1%, 9.8%

> Consider the price of renting a car for a week, with manual transmission but declining the collision damage waiver, in 13 European countries (Table 3.8.12). a. Draw a histogram of this data set. b. Describe the distribution shape. Table 3.8.12: TAB

> The number of small electric motors rejected for poor quality, per batch of 250, were recorded for recent batches. The results were as follows: 3, 2, 7, 5, 1, 3, 1, 7, 0, 6, 2, 3, 4, 1, 2, 25, 2, 4, 5, 0, 5, 3, 5, 3, 1, 2, 3, 1, 3, 0, 1, 6, 3, 5, 41, 1,

> What action would you recommend? Why?

> Should we agree with Billings at the next meeting? Justify your answer by careful analysis of the available data.

> Continuing with the revenue loss data of Table 3.8.11: a. Find the logarithm for each data value. Omit the two firms with zero revenue loss from your answers to this problem. b. Construct a histogram for this data set. c. Describe the distribution shape.

> When the Internal Revenue Service (IRS) tax code was revised in 1986, Congress granted some special exemptions to specific corporations. The U.S. government’s revenue losses due to some of these special transition rules for corporate pr

> Many people do not realize how much a funeral costs and how much these costs can vary from one provider to another. Consider the price of a traditional funeral service with visitation (excluding casket and grave liner) as shown in Table 3.8.10 for the Pu

> Consider the net income as reported by selected firms in Table 3.8.9. a. Construct a histogram. b. Describe the distribution shape. Table 3.8.9: TABLE 3.8.9 Net Income of Selected Firms Firm Net Income ($ Thousands) Bay State Bancorp 1,423 Bedford

> There are many different and varied formats and strategies for radio stations, but one thing they all have in common is the need for an audience in order to attract advertisers. Table 3.8.8 shows the percent of listeners for radio stations in the Albuque

> Consider the compensation paid to CEOs of computer programming, data processing, and other related services firms, as shown in Table 3.8.7. a. Construct a histogram. b. Describe the distribution shape. Table 3.8.7: TABLE 3.8.7 CEOo Compensation for

> Consider the costs charged for treatment of heart failure and shock by hospitals in the Puget Sound area, as shown in Table 3.8.6. a. Construct a histogram. b. Describe the distribution shape. Table 3.8.6: TABLE 3.8.6 Hospital Charges for Heart Fa

> Draw a histogram of the average hospital charge in ($ thousands) for treating a patient who had the diagnosis group “Inguinal & femoral hernia procedures w MCC” for a group of hospitals in Washington State (data accessed at http://wwwdoh.wa.gov/EHSPHL/h

> Consider the percent change in revenues for food-related companies in the Fortune 500, in Table 3.8.5. a. Construct a histogram for this data set. b. Describe the distribution shape. c. Land O’Lakes had the largest decrease, falling by

> Table 2.6.1 shows some items from a human resources database, representing the status of five people on May 3, 2015. a. What is an elementary unit for this data set? b. What kind of data set is this: Univariate, bivariate, or multivariate? c. Which of th

> Look through the data. Do you find anything that calls into question the regression results? Perform further analysis as needed.

> Consider the 20,000 median household income values in the donations database (available at the companion site). These represent the median household income for the neighborhood of each potential donor in the database. a. Construct a histogram. b. Describ

> Consider CREF, the College Retirement Equities Fund, which manages retirement accounts for employees of nonprofit educational and research organizations. CREF manages a large and diversified portfolio in its growth stock account, somewhere around $22.5 b

> Consider the percentage change in stock price of the most active issues traded on the NASDAQ stock exchange, as shown in Table 3.8.3. a. Construct a histogram of this data set. b. Describe the distribution shape. c. Identify the outlier. d. Interpret the

> Business firms occasionally buy back their own stock for various reasons, sometimes when they view the market price as a bargain compared to their view of its true worth. It has been observed that the market price of stock often increases around the time

> Consider the yields (as an interest rate, in percent per year) of municipal bonds, as shown in Table 3.8.1. a. Construct a histogram of this data set. b. Based on the histogram, what values appear to be typical for this group of tax-exempt bonds? c. Desc

> Many countries (but not the United States) have a “value added tax” that is paid by businesses based on how much value they add to a product (e.g. the difference between sales revenues and the cost of materials). This

> Mutual funds that specialize in the stock of natural resources companies showed considerable variation in their performance during the 12-month period ending July 2010. Consider the Rate of Return column in Table 5.5.3. a. Find the average rate of return

> Consider the Internet advertising budgets from problem 1, but expressed in European euros instead of U.S. dollars. Use the exchange rate listed in a recent issue of The Wall Street Journal or another source. Based on your answers to problem 1 (ie, withou

> Table 4.3.1 provides a list of the amounts that your regular customers spent on your products last month: a. Find the average sales per regular customer. b. Find the median and quartiles. c. Draw the box plot. d. Find the outliers, if any. e. Draw the de

> Refer to the data for problem 6. a. Find the critical value from the F table at the 10% level and report the result of the F test at this level. b. Summarize what this F test has told you about the comparative abilities of these additives to reduce waste

> What are the “obvious conclusions” from the hypothesis tests in the regression output?

> Refer to the data for problem 6. Would it be appropriate to use the least-significant-difference test to find out whether Cleen Up has significantly lower waste than Sludge Away (at the 5% level)? Why or why not? Data from problem 6: Three companies ar

> Refer to the data for problem 6. a. Find the F statistic and its numbers of degrees of freedom. b. Interpret the F statistic in terms of how many times more volatile one source of variability is than another. c. Find the critical value from the F table a