Sam Easton started out as a real estate agent in Atlanta ten years ago. After working two years for a national real estate firm, he transferred to Dallas, Texas, and worked for another realty agency....
Two television stations in a market compete with each other for viewing audience. Local programming options for the 5:00 P.M. weekday time slot include a sitcom rerun, an early news program, or a...
Can you use Twitter activity to forecast box office receipts on the opening weekend? The following data (stored in Twitter Movies) indicate the Twitter activity ( want to see) and the receipts ($)...
What was the approximate net change from April 29 to April 30? Express that net change as a monetary amount and as a percent to the nearest tenth. WPO Daily - 695 690 685 680 675 670 665 660 655 650...
Web Mercantile sells many household products through an online catalog. The company needs substantial warehouse space for storing its goods. Plans now are being made for leasing warehouse storage...
In the month preceding the creation of this exercise, the author made 18 phone calls in 30 days. No calls were made on 19 days, 1 call was made on 8 days, and 2 calls were made on 5 days. a. Find the...
An interviewer is given a list of people she can interview. If the interviewer needs to interview 5 people, and if each person (independently) agrees to be interviewed with probability 2/3, what is...
Merrill Lynch recently completed a study regarding the size of online investment portfolios (stocks, bonds, mutual funds, and certificates of deposit) for a sample of clients in the 40 up to 50 years...
The operations manager at a compact fluorescent light bulb (CFL) factory needs to estimate the mean life of a large shipment of CFLs. The manufacturers specifications are that the standard deviation...
There are 25 motels in Goshen, Indiana. The number of rooms in each motel follows: a. Using a table of random numbers (Appendix B.4), select a random sample of five motels from this population. b....
A cola-dispensing machine is set to dispense 9.00 ounces of cola per cup, with a standard deviation of 1.00 ounce. The manufacturer of the machine would like to set the control limit in such a way...
Match each of the following histograms to the correct situation. 1. Test scores for students on an easy test. 2. The numbers of hours of television watched by a large, typical group of Americans. 3....
The probability is 0.314 that the gestation period of a woman will exceed 9 months. In six human births, what is the probability that the number in which the gestation period exceeds 9 months is a....
In Problem 3-35, you helped the medical professionals analyze their decision using expected monetary value as the decision criterion. This group has also assessed their utility for money: U (...
Ethan and Drew went on a 10-day fishing trip. The number of smallmouth bass caught and released by the two boys each day was as follows: (a) Find the population mean and the range for the number of...
Do Americans prefer Coke or Pepsi? A survey was conducted by Public Policy Polling ( PPP) in 2013; the results were as follows: If an American is selected at random, what is the probability that he...
A swimming pool is 20 ft wide, 40 ft long, 3 ft deep at the shallow end, and 9 ft deep at its deepest point. A cross-section is shown in the figure. If the pool is being filled at a rate of...
H & K Electronic Warehouse sells a 12-pack of AAA batteries, and this is a very popular item. Demand for this is normally distributed, with an average of 50 packs per day and a standard deviation of...
In a study entitled How Undergraduate Students Use Credit Cards, it was reported that undergraduate students have a mean credit card balance of $3,173 (Sallie Mae, April 2009). This figure was an...
The mean noise level of 20 areas designated as casualty doors was 63.1 dBA, and the standard deviation is 4.1 dBA. The mean noise level for 24 areas designated as operating theaters was 56.3 dBA, and...
The susceptibility of the root stocks of a variety of orange tree to a specific larva is investigated by a group of researchers. Forty orange trees are exposed to the larva and then examined by the...
A large distributor of oil-well drilling equipment operated over the past two years with EOQ policies based on an annual holding cost rate of 22%. Under the EOQ policy, a particular product has been...
Calculate the random access memory (RAM) in megabytes necessary to store a multidimensional array that is 20 x 40 x 120.This array is double precision, and each value requires a 64-bit word. Recall...
Leverock's Waterfront Steakhouse in Maderia Beach, Florida, uses a questionnaire to ask customers how they rate the server, food quality, cocktails, prices, and atmosphere at the restaurant. Each...
A tank is full of water. Find the work required to pump the water out of the outlet. In Exercises 23 and 24 use the fact that water weighs 62.5 lb/ft3. 21. 22. Im - 3 m - 2 m 3 m 1.5 m 6 m 23. 24. E...
Four electronic printers are selected from a large lot of damaged printers. Each printer is inspected and classified as containing either a major or a minor defect. Let the random variables X and Y...
An article in Environment International (Vol. 18, No. 4, 1992) describes an experiment in which the amount of radon released in showers was investigated. Radon-enriched water was used in the...
Before every flight, the pilot must verify that the total weight of the load is less than the maximum allowable load for the aircraft. The Bombardier Dash 8 aircraft can carry 37 passengers, and a...
Oilco is considering two potential drilling sites for reaching four targets (possible oil wells). The following table provides the preparation costs at each of the two sites and the cost of drilling...
Procter & Gamble has been the leading soap manufacturer in the United States since 1879, when it introduced Ivory soap. However, late in 1991, its major rival, Lever Bros. (Unilever), overtook it by...
A Realtor in Mission Viejo, California, believes that the average price of a house is more than $500 thousand. a. State the null and the alternative hypotheses for the test. b. Open the MV_Houses...
Best known for its testing program, ACT, Inc., also compiles data on a variety of issues in education. In 2012 the company reported that the national college freshman-to-sophomore retention rate at...
A pond drains through a pipe as shown in Figure. Under a number of simplifying assumptions, the following differential equation describes how depth changes with time: dh / dt = d 2 /4 A ( h ) 2 g (...
Using MAD, determine whether the forecast in Problem 5-15 or the forecast in the section concerning Wallace Garden Supply is more accurate. In Problem 5-15, Develop a four-month moving average...
The reading speed of second grade students is approximately normal, with a mean of 90 words per minute (wpm) and a standard deviation of 10 wpm. (a) What is the probability a randomly selected...
Nicol lets the pdf of X be defined by Find (a) The value of c so that f(x) is a pdf. (b) The mean of X (if it exists). (c) The variance of X (if it exists). (d) P(1/2 X 2). 0-x-1, 1 elsewhere f(x)...
Let n = 9 in the T statistic defined in Equation 5.5-2. (a) Find t0.025 so that P(t0.025 T t0.025) = 0.95. (b) Solve the inequality [t0.025 T t0.025] so that is in the middle.
A manufacturing process produces 500 parts per hour. A sample part is selected about every half hour, and after five parts are obtained, the average of these five measurements is plotted on an x...
The employee credit union at State University is planning the allocation of funds for the coming year. The credit union makes four types of loans to its members. In addition, the credit union invests...
The values of Alabama building contracts (in millions of dollars) for a 12-month period follow: 240 350 230 260 280 320 220 310 240 310 240 230 a. Construct a time series plot. What type of pattern...
Use the data in MEAP93.RAW to answer this question. (i) Estimate the model math10 = (0 + (1 log (expend) + (2 lnchprg + u, and report the results in the usual form, including the sample size and...
Hamilton County judges try thousands of cases per year. In an overwhelming majority of the cases disposed, the verdict stands as rendered. However, some cases are appealed, and of those appealed,...
In a multiple regression equation, two independent variables are considered, and the sample size is 25. The regression coefficients and the standard errors are as follows. b1 = 2.676 sb1 = 0.56 b2 =...
A certain raw material is classified as to moisture content X (in percent) and impurity Y (in percent). Let X and Y have the joint pmf given by (a) Find the marginal pmfs, the means, and the...
A TiW layer is deposited on a substrate using a sputtering tool. Table 6E.14 contains layer thickness measurements (in angstroms) on 20 subgroups of four substrates. (a) Setup x and R control charts...
A measurement systems experiment involving 20 parts, three operators, and two measurements per part is shown in Table 8E.12. (a) Estimate the repeatability and reproducibility of the gauge (b) What...
According to the Open Doors Report, 9.5% of all full-time U.S. undergraduate students study abroad (Institute of International Education, November 14, 2011). Assume that 60% of the undergraduate...
For the following situations, would you collect information using a sample or a population? Why? a. Statistics 201 is a course taught at a university. Professor Rauch has taught nearly 1,500 students...
The null and alternate hypotheses are: H 0 : =0 H 1 : 0 The following paired observations show the number of traffic citations given for speeding by Officer Dhondt and Officer Meredith of the...
The National Football League (NFL) records a variety of performance data for individuals and teams. To investigate the importance of passing on the percentage of games won by a team, the following...
Suppose you really want the Hope Solo picture. How many boxes of cereal do you need to buy to be pretty sure of getting at least one? First, define what "pretty sure" means to you. Then run a...
A sample of 100 customers of Montana Gas and Electric resulted in the following frequency distribution of monthly charges. Amount ($) Number 049 ......... 13 5099 ......... 22 100149 ........ 34...
The Electrocomp Corporation manufactures two electrical products: air conditioners and large fans. The assembly process for each is similar in that both require a certain amount of wiring and...
In Exercise 25, we saw that in 2013 Harvard accepted about 5.8% of its applicants, Dartmouth 10%, and Penn 12.1%. Jorge has applied to all three. He figures that his chances of getting into at least...
The data set 401KSUBS.RAW contains information on net financial wealth (nettfa), age of the survey respondent (age), annual family income (inc), family size (fsize), and participation in certain...
Martin-Pullin Bicycle Corp. (MPBC), located in Dallas, is a wholesale distributor of bicycles and bicycle parts. Formed in 1981 by cousins Ray Martin and Jim Pullin, the firm's primary retail outlets...
In a recent Pew poll of 1500 adults, 52% of the respondents said that the use of marijuana should not be made legal. In the same poll, 23% of the respondents said that the use of marijuana for...
Why wouldn't a company always store large quantities of inventory to eliminate shortages and stockouts?
After seeing countless commercials claiming one can get cheaper car insurance from an online company, a local insurance agent was concerned that he might lose some customers. To investigate, he...
An elastic band is hung on a hook and a mass is hung on the lower end of the band. When the mass is pulled downward and then released, it vibrates vertically. The equation of motion is s = 2 cos t +...
The amount of a uniformly distributed radioactive contaminant contained in a close reactor is measured by its concentration c (Becquerel/liter or Bq/L). The contaminant decreases at a decay rate...
Amy Lloyd is interested in leasing a new Saab and has contacted three automobile dealers for pricing information. Each dealer offered Amy a closed-end 36-month lease with no down payment due at the...
The following data give the starting salary for students who recently graduated from a local university and accepted jobs soon after graduation. The starting salary, grade-point average (GPA), and...
Using Table G, find the values for x 2 left and x 2 right . a. a = 0.05, n = 12 b. a = 0.10, n = 20 c. a = 0.05, n = 27 d. a = 0.01, n = 6 e. a = 0.10, n = 41
A company that franchises coffee houses conducted taste tests for a new coffee product. The company prepared four blends and randomly chose individuals to do a taste test and state which of the four...
The number of shark attacks and deaths over a recent 5-year period is shown. Find the mean, median, mode, midrange, variance, and standard deviation for the data. Which data set is more variable?...
Management of the Telemore Company is considering developing and marketing a new product. It is estimated to be twice as likely that the product would prove to be successful as unsuccessful. It it...
Recall that the velocity of the falling parachutist can be computed by [Eq. (1.10)], v(t) = 8m/c (1
A manufacturer of integrated circuits is planning production for the next four months. The forecast demand for the circuits is shown in the following table. At the beginning of September, the...
In the last chapter, we looked at three outliers arising from a plot of Average Wind Speed by Month in the Hopkins Forest. Each was associated with an unusually strong storm, but which was the most...
What is a reasonable explanation for the gap between the quarters with weights between 5.5 grams and 5.8 grams and the group of quarters with weights between 6.0 grams and 6.4 grams? Required Answer...
A retail study by Deloitte revealed that 54% of adults surveyed believed that plastic, non-compostable shopping bags should be banned. Suppose 41% of adults regularly recycle aluminum cans and...
Gapco manufactures three products, whose daily labor and raw material requirements are given in the following table. The profits per unit of the three products are $25, $30, and $22, respectively....
Bill First, general manager of Worthmore Department Store, has estimated that every hour of customer time spent waiting in line for the sales clerk to become available costs the store $100 in lost...
Suppose that a single-sampling plan with n = 150 and c = 2 is being used for receiving inspection where the supplier ships the product in lots of size N = 3,000. (a) Draw the OC curve for this plan....
A sample of 10 NCAA college basketball game scores provided the following data. a. Compute the mean and standard deviation for the points scored by the winning team. b. Assume that the points scored...
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...
For each of the following, categorize the nature of the data using one of these three descriptions: (1) Discrete because the number of possible values is finite; (2) Discrete because the number of...
A packaging process is supposed to ll small boxes of raisins with approximately 50 raisins so that each box will weigh the same. However, the number of raisins in each box will vary. Suppose 100...
The manufacturing company in Problem 2.44 also produces electric insulators. If the insulators break when in use, a short circuit is likely to occur. To test the strength of the insulators,...
Fifty percent of the customers who go to Sears Auto Center for tires buy four tires and 30% buy two tires. Moreover, 18% buy fewer than two tires, with 5% buying none. a. What is the probability that...
The time between calls to a plumbing supply business is exponentially distributed with a mean time between calls of 15 minutes. (a) What is the probability that there are no calls within a 30- minute...
For most products, higher prices result in a decreased demand, whereas lower prices result in an increased demand (economists refer to such products as normal goods). Let d = annual demand for a...
Recall the TJ Inc.'s problem (Chapter 2, Problem 28). Letting W = jars of Western Foods Salsa M = jars of Mexico City Salsa Leads to the formulation: Max 1W + 1.25M s.t. 5W + 7M ¤ 4480 Whole...
After buying a computer system, Sim Thomas must decide whether to purchase (1) A complete maintenance (or service) policy at a cost of $500, which would cover all maintenance costs; (2) A partial...
A food manufacturer claims that eating its new cereal as part of a daily diet lowers total blood cholesterol levels. The table shows the total blood cholesterol levels (in milligrams per deciliter of...
Refer to the gasoline sales time series data in Table. a. Compute four- and five-week moving averages for the time series. b. Compute the MSE for the four- and five-week moving average forecasts. c....
A manufacturer produces both a deluxe and a standard model of an automatic sander designed for home use. Selling prices obtained from a sample of retail outlets follow. a. The manufacturer's...
The Philbrick Company has two plants on opposite sides of the United States. Each of these plants produces the same two products and then sells them to wholesalers within its half of the country. The...
Use the data in APPLE.RAW to answer this question. (i) Define a binary variable as ecobuy = 1 if ecolbs > 0 and ecobuy = 0 if ecolbs = 0. In other words, ecobuy indicates whether, at the prices...
Suppose that Ralph gets a strike when bowling 30% of the time. (a) What is the probability that Ralph gets two strikes in a row? (b) What is the probability that Ralph gets a turkey (three strikes in...
A market researcher working for the bank in Exercise 2 wants to know if the distribution of applications by card is the same for the past three mailings. She takes a random sample of 200 from each...
The derivative of (x) = l/ (l 3 x2 ) 2 is given by 6x / (1 3x 2 ) 2 . Do you expect to have difficulties evaluating this function at x = 0.577? Try it using 3-and 4-digit arithmetic with chopping.
The following payoff table shows profit for a decision analysis problem with two decision alternatives and three states of nature: a. Construct a decision tree for this problem. b. If the decision...
A random sample of n1 = 16 communities in western Kansas gave the following information for people under 25 years of age: x1: Rate of hay fever per 1000 population for people under 25 A random sample...
Use the data in 401KSUBS.RAW for this question, restricting the sample to fsize = 1. (i) To the model estimated in Table 8.1, add the interaction term, e401k ( inc. Estimate the equation by OLS and...
A civil engineer is analyzing the compressive strength of concrete. Compressive strength is normally distributed with 2 = 1000(psi)2. A random sample of 12 specimens has a mean compressive strength...
Consider the following problem: A box with an open top is to be constructed from a square piece of cardboard, 3 ft wide, by cutting out a square from each of the four corners and bending up the...
A manufacturer of bolts has a quality- control policy that requires it to destroy any bolts that are more than 2 standard deviations from the mean. The quality-control engineer knows that the bolts...
The Quality Control Department employs five technicians during the day shift. Listed below is the number of times each technician instructed the production foreman to shut down the manufacturing...