The Car Repair Ratings website provides consumer reviews and ratings for garages in the United States and Canada. The time customers wait for service to be completed is one of the categories rated....
Suppose the scores earned on Professor McArthurs third statistics exam are normally distributed with mean 64 and standard deviation 8. Professor McArthur wants to curve the exam scores as follows:...
Reconsider Prob. 22.2-1. Christine has done more detailed planning for this project and so now has the following expanded activity list: Construct the new project network. Immediate Estimated...
Researchers for a manufacturer of barometers (devices to measure atmospheric pressure) read each of 50 barometers at the same time of day. The mean of the readings is 30.4 (inches of mercury) with a...
The file lists the calories and sugar, in grams, in one serving of seven breakfast cereals: a. Compute the covariance. b. Compute the coefficient of correlation. c. Which do you think is more...
The registrar of a college with a population of N = 4,000 full-time students is asked by the president to conduct a survey to measure satisfaction with the quality of life on campus. The following...
Assembly times for components must be understood in order to level the stages of a production process. Construct both a histogram and a frequency polygon for the following assembly time data and...
The Grocery Manufacturers of America reported that 76% of consumers read the ingredients listed on a products label. Assume the population proportion is p = .76 and a sample of 400 consumers is...
A group of educators want to determine how effective tutoring is in raising students grades in a math class, so they arrange free tutoring for those who want it. Then they compare final exam grades...
A meat packing house is creating a new variety of hot dog for the low-calorie, low-fat, low-cholesterol market. This new hot dog will be made of beef and pork, plus either chicken, turkey, or both....
The potential buyer of a particular engine requires (among other things) that the engine start successfully 10 consecutive times. Suppose the probability of a successful start is 0.990. Let us assume...
Refer to the Buena School District bus data. a. Select the variable for the number of miles traveled last month. Conduct a test of hypothesis to determine whether the mean number of miles traveled is...
In a classic study, Milgram et al. lost stamped envelopes with fictitious addresses (Medical Research Association, Personal Address, Friends of Communist Party, and Friends of Nazi Party).* One...
Data for the progression of college students at a particular college are summarized in the following matrix of transition probabilities. a. What states are absorbing states? b. Interpret the...
An analyst from an energy research institute in California wishes to precisely estimate the 99% confidence interval for the average price of unleaded gasoline in the state. In particular, she does...
Brand managers become concerned if they discover that customers are aging and gradually moving out of the high-spending age groups. For example, the average Cadillac buyer is older than 60, past the...
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...
Christine Phillips is in charge of planning and coordinating next springs sales management training program for her company. Christine has listed the following activity information for this project:...
Johnson Marketing is interested in producing and selling an innovative new food processor. The decision they face is the typical "make or buy" decision often faced by manufacturers. On one hand,...
A laterally insulated homogeneous bar with ends at x = 0 and x = 1 has initial temperature 0. Its left and is kept at 0, whereas the temperature at the right end varies sinusoidally according to u(t,...
The following data give the selling price, square footage, number of bedrooms, and age of houses that have sold in a neighborhood in the past 6 months. Develop three regression models to predict the...
A production process manufactures items with weights that are normally distributed with mean 15 pounds and standard deviation 0.1 pound. An item is considered to be defective if its weight is less...
Susan Jones would like her investment portfolio to be selected from a combination of three stocks Alpha, Beta, and Gamma. Let variables A, B, and G denote the percentages of the portfolio devoted to...
Ronald Kivetsky bought a new car and received these price quotes from his insurance company. a. What is the annual premium? b. What is the semiannual premium? c. How much less would Ronald's...
Consider the traffic accident data set shown in Table 7.1. (a) Show a binarized version of the data set. (b) What is the maximum width of each transaction in the binarized data? (c) Assuming that...
Water flows in and out of a storage tank. A graph of the rate of change r(t) of the volume of water in the tank, in liters per day, is shown. If the amount of water in the tank at time t = 0 is...
There are 100 employees at Kiddie Carts International. Fifty-seven of the employees are hourly workers, 40 are supervisors, 2 are secretaries, and the remaining employee is the president. Suppose an...
A manager at an ice cream store is trying to determine how many customers to expect on any given day. Overall business has been relatively steady over the past several years, but the customer count...
The Future Government Club wants to sponsor a panel discussion on the upcoming national election. The club wants to have four of its members lead the panel discussion. To be fair, however, the panel...
Jeff Parent is a statistics instructor who participates in triathlons. Listed below are times (in minutes and seconds) he recorded while riding a bicycle for five laps through each mile of a 3-mile...
Anticipated consumer demand in a restaurant for free-range steaks next month can be modeled by a normal random variable with mean 1,200 pounds and standard deviation 100 pounds. a. What is the...
An American Automobile Association (AAA) study investigated the question of whether a man or a woman was more likely to stop and ask for directions (AAA, January 2006). The situation referred to in...
A small backpack manufacturer carries four different models of backpacks, made of canvas, plastic, nylon, and leather. The bookstore, which will exclusively sell the backpacks, expects to be able to...
According to Chemical Engineering Progress (Nov. 1990), approximately 30% of all pipe work failures in chemical plants are caused by operator error. (a) What is the probability that out of the next...
One mechanic services 5 drilling machines for a steel plate manufacturer. Machines break down on an average of once every 6 working days, and breakdowns tend to follow a Poisson distribution. The...
Consider the minute clinic waiting time data in Exercise 6.66. These data may not be normally distributed. Set up a EWMA control chart using ï¬ï = 0.1 for monitoring this process. Does...
The manager of the Fore and Aft Marina in Problem 16 wants to investigate the possibility of enlarging the docking facility so that two boats can stop for gas and servicing simultaneously. Assume...
Coren Chemical, Inc., develops industrial chemicals that are used by other manufacturers to produce photographic chemicals, preservatives, and lubricants. One of their products, K-1000, is used by...
The 2012 Restaurant Industry Forecast takes a closer look at todays consumers. Based on a 2011 National Restaurant Association survey, consumers are divided into three segments (optimistic, cautious,...
Shortys Muffler advertises it can install a new muffler in 30 minutes or less. However, the work standards department at corporate headquarters recently conducted a study and found that 20% of the...
Suppose there are 100 students in your accounting class, 10 of whom are left-handed. Two students are selected at random. a. Draw a probability tree and insert the probabilities for each branch. What...
In a random sample of 250 toner cartridges, the mean number of pages a toner cartridge can print is 4302 and the standard deviation is 340. (a) Suppose a histogram of the data indicates that the...
A company uses the following acceptance-sampling procedure. A sample equal to 10% of the lot is taken. If 2% or less of the items in the sample are defective, the lot is accepted; otherwise, it is...
A production process contains a machine that deteriorates rapidly in both quality and output under heavy usage, so that it is inspected at the end of each day. Immediately after inspection, the...
In a study to isolate both gauge repeatability and gauge reproducibility, two operators use the same gauge to measure ten parts three times each. The data are shown in Table 8E.10. (a) Estimate gauge...
A Poisson distribution with m = 1.2 governs the number of fireflies that flash in a 10 second period during an August evening in the yard. Determine the probability that; (a) 2 fireflies flash. (b)...
An inspector of flow metering devices used to administer fluid intravenously will perform a hypothesis test to determine whether the mean flow rate is different from the flow rate setting of 200...
In 1992, George Brown started the Old Oregon Wood Store to manufacture Old Oregon tables. Each table is carefully constructed by hand using the highest-quality oak. Old Oregon tables can support more...
The American Society for Quality (ASQ) conducted a salary survey of all its members. ASQ members work in all areas of manufacturing and service-related institutions, with a common theme of an...
An article in Human Factors (June 1989) presented data on visual accommodation (a function of eye movement) when recognizing a speckle pattern on a high-resolution CRT screen. The data are as...
A textile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms. The company wishes...
An object of mass m is moving horizontally through a medium which resists the motion with a force that is a function of the velocity; that is, where v = v(t) and s = s (t) represent the velocity and...
In exercise 4, the following estimated regression equation relating sales to inventory investment and advertising expenditures was given. y = 25 + 10x1 + 8x2 The data used to develop the model came...
A real-estate broker in Washington, DC, purchased 3 two-bedroom houses in a depressed market for a combined cost of $1,000,000. He expects the cleaning and repair costs on each house to average...
Dwight Moody is the manager of a large farm with 1,000 acres of arable land. For greater efficiency, Dwight always devotes the farm to growing one crop at a time. He now needs to make a decision on...
A bookstore at the Hartsfield-Jackson Airport in Atlanta sells reading materials (paperback books, newspapers, magazines) as well as snacks (peanuts, pretzels, candy, etc.). A point-of-sale terminal...
PVC pipe is manufactured with a mean diameter of 1.01 inch and a standard deviation of 0.003 inch. Find the probability that a random sample of n = 9 sections of pipe will have a sample mean diameter...
Embassy Publishing Company received a six-chapter manuscript for a new college textbook. The editor of the college division is familiar with the manuscript and estimated a 0.65 probability that the...
Ridgewood Savings Bank charges a $27 per check overdraft protection fee. On July 8, Nancy had $1,400 in her account. Over the next four days, the following checks arrived for payment at her bank:...
Consider the data set shown in Table 7.13. Suppose we are interested in extracting the following association rule: {α1 ¤ Age ¤ α2, Play Piano = Yes} {Enjoy...
Recent research has shown that creative people are more likely to cheat than their less creative counterparts (Gino & Ariely, 2010). Participants in the study first completed creativity assessment...
A survey of 1,085 adults asked, "Do you enjoy shopping for clothing for yourself?" The results (data extracted from "Split Decision on Clothes Shopping," USA Today, January 28, 2011, p. IB) indicated...
It has been said that each LP problem that has a feasible region has an infinite number of solutions. Explain.
CRA CDs Inc. wants the mean lengths of the cuts on a CD to be 135 seconds (2 minutes and 15 seconds). This will allow the disk jockeys to have plenty of time for commercials within each 10-minute...
You are a new hire at Laurel Woods Real Estate, which specializes in selling foreclosed homes via public auction. Your boss has asked you to use the following data (mortgage balance, monthly...
Suppose the mean wait-time for a telephone reservation agent at a large airline is 43 seconds. A manager with the airline is concerned that business may be lost due to customers having to wait too...
A personnel specialist with a large accounting firm is interested in determining the effect of seniority (the number of years with the company) on hourly wages for secretaries. She selects at random...
Nassau County is located approximately 25 miles east of NewYork City. The data organized and stored in GlenCove include the appraised value, land area of the property in acres, and age, in years, for...
What effect did the smoothing constant have on the forecast for Cool-Man air conditioners? Which smoothing constant gives the most accurate forecast? Data from Sales of Cool-Man air conditioners have...
The Alfredo Fragrance Company produces only one product, a perfume called Hint of Elegance. Hint of Elegance consists of two secret ingredients blended into an exclusive fragrance, which is marketed...
A study of Kickstarter projects showed that 54.2% were successful, that is, achieved its goal and raised at least the targeted goal amount. In an effort to identify network dynamics that influences...
In a survey conducted by CareerBuilder.com, employers were asked if they had ever sent an employee home because they were dressed inappropriately (June 17, 2008, www.careerbuilder.com). A total of...
A Fortune study found that the variance in the number of vehicles owned or leased by subscribers to Fortune magazine is .94. Assume a sample of 12 subscribers to another magazine provided the...
In Exercise 6 of Chapter 2, data on numbers of publications were given for an SRS of 50 faculty members. Not all departments were represented, however, in the SRS. The SRS contained several faculty...
The article mentioned in Problem 7.28 reported that the stock market in Germany had a mean return of 2.7% in 2014. Assume that the returns for stocks on the German stock market were distributed...
Refer to the Billys Bank situation in Problem 12-24. Billy is considering adding a second teller (who would work at the same rate as the first) to reduce the waiting time for customers, and he...
Consider Christine Phillips project involving planning and coordinating next springs sales management training program for her company as described in Prob. 22.2-1. After constructing the project...
A company uses four special tank trucks to deliver four different gasoline products to customers. Each tank has five compartments with different capacities: 500, 750, 1200, 1500, and 1750 gallons....
USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 40 male...
Find the positive square root of 18 using the false-position method to within s = 0.5%. Employ initial guesses of xl = 4 and xu = 5.
One in five 18-year-old Americans has not graduated from high school (The Wall Street Journal, April 19, 2007). A mayor of a northeastern city comments that its residents do not have the same...
Match the linear correlation coefï¬cient to the scatter diagram. The scales on the x- and y-axes are the same for each diagram. (a) r = -0.969 (b) r = -0.049 (c) r = -1 (d) r = -0.992...
A sample was selected of 506 workers who currently receive two weeks of paid vacation per year. These workers were asked if they were willing to accept a small pay cut to get an additional week of...
Weenies and Buns is a food processing plant which manufactures hot dogs and hot dog buns. They grind their own flour for the hot dog buns at a maximum rate of 200 pounds per week. Each hot dog bun...
A large corporation has spent considerable time developing employee performance rating scales to evaluate an employees job performance on a regular basis so major adjustments can be made when needed...
The figure shows a lamp located three units to the right of the -axis and a shadow created by the elliptical region x2 + 4y2 x+ 4y = 5
Nutrition Foods A and B have 600 and 500 calories, contain 15g and 30g of protein, and cost $1.80and $2.10 per unit, respectively, Find the minimum cost diet of at least 3900 calories containing at...
Linda Lechner has just been severely chastised for her inventory policy. Sue Surrowski, her boss, believes that the service level should be either 95% or 98%. Compute the safety stock levels for a...
The DeBourgh Manufacturing Company was founded in 1909 as a metal-fabricating company in Minnesota by the four Berg brothers. In the 1980s, the company ran into hard times, as did the rest of the...
In a recent poll, the Gallup Organization found that 45% of adult Americans believe that the overall state of moral values in the United States is poor. Suppose a survey of a random sample of 500...
University Toys has developed a series of Engineering Professor Action Figures for the local engineering school and management needs to decide how to market the dolls in the face of uncertainty about...
The pie chart shows a monthly utility budget. a. Suppose that $800 was budgeted for the month. Determine the exact amount for each category. b. Suppose that $117 was budgeted for water. What would be...
Bank of Americas Consumer Spending Survey collected data on annual credit card charges in seven different categories of expenditures: transportation, groceries, dining out, household expenses, home...
Assume that student volunteers were assigned arbitrarily (according to a coin toss) either to be trained to meditate or to behave as usual. To deter-mine whether meditation training (the independent...
Consider the Costello Music Company scenario presented in Problem 20 and the following quarterly sales data: a. Compute the seasonal indexes for the four quarters. b. When does Costello Music...
Western Ranchman outfitters (WRO), a family-owned and operated mail order and retail store business in Cheyenne, Wyoming, bills itself as "The Nation's Finest Western Store" and carries high-quality...
An oil company produces three brands of oils: Regular, Multi grade, and Supreme. Each brand of oil is composed of one or more of four crude stocks, each having a different viscosity index. The...
The British government has stepped up its information campaign regarding foot and mouth disease by mailing brochures to farmers around the country. It is estimated that 99% of Scottish farmers who...
An assembly consists of two mechanical components. Suppose that the probabilities that the first and second components meet specifications are 0.95 and 0.98. Assume that the components are...
Let g(x) f(t) dt, where f is the function whose graph is shown. (a) At what values of do the local maximum and minimum values of occur? (b) Where does attain its absolute maximum value? (c) On what...