The personal computer industry is very fast moving, and technology provides motivation for customers to upgrade with new computers every few years. Brand loyalty is very important, and companies try to do things to keep their customers happy. However, some current customers will switch to a different company. Three particular brands—Doorway, Bell, and Kumpaq—hold the major shares of the market. People who own Doorway computers will buy another Doorway 80% of the time, while the rest will switch to the other companies in equal proportions. Owners of Bell computers will buy Bell again 90% of the time, while 5% will buy Doorway and 5% will buy Kumpaq. About 70% of the Kumpaq owners will make Kumpaq their next purchase while 20% will buy Doorway and the rest will buy Bell. If each brand currently has 200,000 customers who plan to buy a new computer in the next year, how many computers of each type will be purchased?
> Why are and R-charts usually used hand in hand?
> When set at the standard position, Autopitch can throw baseballs toward a batter at an average speed of 60 mph. Autopitch devices are made for both major- and minor-league teams to help them improve their batting averages. Autopitch executives take sam
> Ray Cahn man is the proud owner of a 1955 sports car. On any given day, Ray never knows whether his car will start. Ninety percent of the time it will start if it started the previous morning, and 70% of the time it will not start if it did not start t
> Find the inverse of each of the following matrices:
> Every commercial airline pilot visually inspects his/ her airplane before flying. If the number of visible defects (known as marks) exceeds a certain prescribed limit, the pilot can call for maintenance, causing flight delays or even flight cancellatio
> V. S. Industries in Parkersburg, West Virginia, is a small manufacturer of military-grade hybrid microcircuits. One of the many quality assurance procedures required by Military Standard 883 (MILSTD- 883) for hybrid microcircuits is known as nondestruc
> Cyber security is an area of increasing concern. The National Security Agency (NSA) monitors the number of hits at sensitive websites. When the number of hits is much larger than normal, there is cause for concern, and further investigation is warrante
> A new president at Big State University has made student satisfaction with the enrollment and registration process one of her highest priorities. Students must see an advisor, sign up for classes, obtain a parking permit, pay tuition and fees, and buy
> Kate Drew has been hand-painting wooden Christmas ornaments for several years. Recently, she has hired some friends to help her increase the volume of her business. In checking the quality of the work, she notices that some slight blemishes occasionall
> For Problem 15-16, develop upper and lower control limits for the range. Do these samples indicate that the process is in control? Problem 15-16: Colonel Electric is a large company that produces light bulbs and other electrical products. One parti
> The hit Broadway musical Jefferson is playing at the Richard Rodgers Theatre. Its producers have determined that if it is sold out on any one night, then there is a 96% chance that it will be sold out on the next night. Moreover, if it is not sold out
> Lulu is a surfer who lives in Conway, South Carolina. Through experience, she has determined the transition probabilities for surf conditions from any one day to the next at nearby North Myrtle Beach: Determine the equilibrium probabilities of g
> The following digraph represents the changes in weather from one day to the next in Lowell, Massachusetts. Determine the associated transition matrix and the overall percentage of sunny days.
> What are the major steps in the simulation process?
> The following digraph represents the changes in weather from one day to the next in Erie, Pennsylvania. Determine the associated transition matrix and the probability that it will be cloudy in 3 days given that it is cloudy today.
> Find
> Set up both the vector of state probabilities and the matrix of transition probabilities given the following information: • Store 1 currently has 40% of the market; store 2 currently has 60% of the market. • In each period, store 1 customer
> In Section 14.6, we investigated an accounts receivable problem. How would the paid category and the bad debt category change with the following matrix of transition probabilities?
> Brenda’s Bicycle and Surfboard Rentals leases quad-bikes each day from a supplier and rents them to customers who use them along Seawall Boulevard in Galveston, Texas. Each day, Brenda leases 30 quad-bikes from her supplier at a cost of $4 per qu
> Draw a flow diagram to represent the logic and steps of simulating barge arrivals and unloadings at the Port of New Orleans. For a refresher in flowcharts, see Figure 13.3. Figure 13.3: /
> Upon arrival at the Sunkist Gate at Naval Base Ventura County in Port Hueneme, California, there are two security guards, each assigned to one of the two vehicular lanes that lead up to the gate, to check the identification (i.e., the military Common A
> When additional band members arrived to help at the car wash (see Problem 12-32), it was decided that two cars should be washed at a time instead of just the one. Both work crews would work at the same rate. Problem 12-32: The Clear Brook High Scho
> The Clear Brook High School band is holding a car wash as a fund-raiser to buy new equipment. The average time to wash a car is 4 minutes, and the time is exponentially distributed. Cars arrive at a rate of one every 5 minutes (or 12 per hour), and the
> The following table represents a network with the arcs identified by their starting and ending nodes. Draw the network and use the minimal-spanning tree technique to find the minimum distance required to connect these nodes. ARC DISTANCE 1–2
> List three ways in which random numbers may be generated for use in a simulation.
> The average number of customers in the system in the single-channel, single-phase model described in Section 12.4 is L = μ μ−λ Show that for m = 1 server, the multichannel queuing model in Section 12.5, is identical to the s
> Customers arrive at an automated coffee vending machine at a rate of 4 per minute, following a Poisson distribution. The coffee machine dispenses a cup of coffee in exactly 10 seconds. (a). What is the average number of people waiting in line? (b).
> Mr. Fetterolf (see Problem 12-38) is considering changing the queuing characteristics of his shop. Instead of selecting a number for the first available barber, a customer will be able to select which barber he or she prefers upon arrival. Assuming tha
> Fetterolf's Barber Shop is a popular haircutting place near the campus of Penn State. Four barbers work full-time and spend an average of 15 minutes on each customer. Customers arrive all day long, at an average rate of 12 per hour. When they enter
> During peak times, the entry gate at a large amusement park experiences an average arrival of 500 customers per minute, according to a Poisson distribution. The average customer requires 4 seconds to be processed through the entry gate. The park’
> An operator processes jobs on a first-come, first served basis. The jobs have Poisson arrival rates, with an average of 6 minutes between arrivals. The objective is to process these jobs so that they spend no more than 8 minutes, on average, in the sys
> The director of security wants to connect security video cameras to the main control site from five potential trouble locations. Ordinarily, cable would simply be run from each location to the main control site. However, because the environment is pote
> Using the data in Solved Problem 10-3, develop a spreadsheet for a two-period weighted moving average forecast with weights of 0.6 1w12 for the most recent period and 0.4 (w2) for the other period. Note these weights sum to 1, so the forecast is simply
> In Solved Problem 10.3, nonlinear programming was used to find the best value for the smoothing constant, a, in an exponential smoothing forecasting problem. To see how much the MAD can vary due to the selection of the smoothing constant, use Excel and
> The XYZ Corporation is expanding its market to include Texas. Each salesperson is assigned to potential distributors in one of five different areas. It is anticipated that the salesperson will spend about three to four weeks in the assigned area. A state
> What is Monte Carlo simulation? What principles underlie its use, and what steps are followed in applying it?
> Summertime Tees sells two very popular styles of embroidered shirts in southern Florida: a tank top and a regular T-shirt. The cost of the tank top is $6, and the cost of the T-shirt is $8. The demand for these is sensitive to the price, and historical
> Pat McCormack, a financial advisor for Investors R Us, is evaluating two stocks in a particular industry. He wants to minimize the variance of a portfolio consisting of these two stocks, but he wants to have an expected return of at least 9%. After obt
> During the busiest season of the year, Green-Gro Fertilizer produces two types of fertilizers. The standard type (X) is just fertilizer, and the other type (Y) is a special fertilizer and weed-killer combination. The following model has been developed
> Motorcross of Wisconsin produces two models of snowmobiles, the XJ6 and the XJ8. In any given production-planning week, Motorcross has 40 hours available in its final testing bay. Each XJ6 requires 1 hour to test and each XJ8 takes 2 hours. The revenue
> Hinkel Rotary Engine, Ltd., produces four- and six cylinder models of automobile engines. The firm’s profit for each four-cylinder engine sold during its quarterly production cycle is $1,800 - $50X1, where X1 is the number sold. Hinkel makes $2,4
> Billy’s Bank is the only bank in a small town in Arkansas. On a typical Friday, an average of 10 customers per hour arrives at the bank to transact business. There is one single teller at the bank, and the average time required to transact busine
> Refer to the Billy’s 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 assumes that this will cut the waiting time in half.
> An Oklahoma manufacturer makes two products: speaker telephones 1X12 and pushbutton telephones 1X22. The following goal programming model has been formulated to find the number of each to produce each day to meet the firm’s goals: Minimize P1d1-
> The cellular phone industry is very competitive. Two companies in the greater Lubbock area, Horizon and Local Cellular, are constantly battling each other in an attempt to control the market. Each company has a 1-year service agreement. At the end of e
> Hervis Rent-A-Car has three car rental locations in the greater Houston area: the North side branch, the West End branch, and the Suburban branch. Customers can rent a car at any of these places and return it to any of the others without any additional
> How do the three types of integer programming problems differ? Which do you think is most common, and why?
> Professor Green gives 2-month computer programming courses during the summer term. Students must pass a number of exams to pass the course, and each student is given three chances to take the exams. The following states describe the possible situation
> Monohan Machinery specializes in developing weed-harvesting equipment that is used to clear small lakes of weeds. George Monohan, president of Monohan Machinery, is convinced that harvesting weeds is far better than using chemicals to kill weeds. Chemi
> Refer to the real estate investment situation in Problem 10.17. Problem 10.17: A real estate developer is considering three possible projects: a small apartment complex, a small shopping center, and a mini-warehouse. Each of these requires differen
> The following are the activity times for the project in Problem 11-16. Find the earliest, latest, and slack times for each activity. Then find the critical path. ACTIVITY TIME (DAYS) A …………………&hellip
> Jean Walker is making plans for spring break at the beaches in Florida. In applying techniques she learned in her quantitative methods class, she has identified the activities that are necessary to prepare for her trip. The following table lists the ac
> The University of South Wisconsin has had steady enrollments over the past 5 years. The school has its own bookstore, called University Book Store, but there are also three private bookstores in town: Bill’s Book Store, College Book Store, and Ba
> Trapeze Investments is a venture capital firm that is currently evaluating six different investment opportunities. There is not sufficient capital to invest in all of these, but more than one will be selected. A 0–1 integer programming model is p
> Shader Storage Technologies produces refrigeration units for food producers and retail food establishments. The overall average temperature that these units maintain is 46° Fahrenheit. The average range is 2° Fahrenheit. Samples of six are take
> Sid Davidson is the personnel director of Babson and Willcount, a company that specializes in consulting and research. One of the training programs that Sid is considering for the middle-level managers of Babson and Willcount is leadership training. Si
> What are the assumptions underlying common queuing models?
> For the post office in Problem 12-17, a second drive through window is being considered. A single line would be formed, and as a car reached the front of the line it would go to the next available clerk. The clerk at the new window works at the same rate
> Automobiles arrive at the drive-through window at a post office at the rate of four every 10 minutes. The average service time is 2 minutes. The Poisson distribution is appropriate for the arrival rate and service times are exponentially distributed. (
> Ashley’s Department Store in Kansas City maintains a successful catalog sales department in which a clerk takes orders by telephone. If the clerk is occupied on one line, incoming phone calls to the catalog department are answered automatically by a reco
> The wheat harvesting season in the American Midwest is short, and most farmers deliver their truckloads of wheat to a giant central storage bin within a 2-week span. Because of this, wheat-filled trucks waiting to unload and return to the fields have bee
> A university cafeteria line in the student center is a self-serve facility in which students select the food items they want and then form a single line to pay the cashier. Students arrive at the cashier at a rate of about four per minute according to a
> Mike Dreskin manages a large Los Angeles movie theater complex called Cinema I, II, III, and IV. Each of the four auditoriums plays a different film; the schedule is set so that starting times are staggered to avoid the large crowds that would occur if a
> From historical data, Harry’s Car Wash estimates that dirty cars arrive at the rate of 10 per hour all day Saturday. With a crew working the wash line, Harry figures that cars can be cleaned at the rate of one every 5 minutes. One car at a time is cleane
> The Rockwell Electronics Corporation retains a service crew to repair machine breakdowns that occur on an average of
> The Schmedley Discount Department Store has approximately 300 customers shopping in its store between 9 a.m. and 5 p.m. on Saturdays. In deciding how many cash registers to keep open each Saturday, Schmedley’s manager considers two factors: customer wait
> The Laurenster Corporation has determined the client will pay it a $10,000 bonus if it completes the project in Problem 11-37 in 14 weeks or less. The associated normal times and costs as well as the crash times and costs are shown below. Considering th
> Briefly describe PERT/Cost and how it is used.
> The Laurenster Corporation needs to perform the tasks in the following list. Develop the associated PERT network diagram, and determine the probability that the project will be complete in 16 weeks or less. MOST IMMEDIATE OPTIMISTIC LIKELY PESSIMIST
> The L. O. Gystics Corporation is in need of a new regional distribution center. The planning for this project is in the early stages, but the activities have been identified, along with their predecessors and their activity times in weeks. The table belo
> The managing partner of the Scott Corey accounting firm (see Problem 11-34) has decided that the system must be up and running in 16 weeks. Consequently, information about crashing the project was put together and is shown in the following table: Proble
> The following costs have been estimated for the activities in a project: (a). Develop a cost schedule based on earliest start times. (b). Develop a cost schedule based on latest start times. (c). Suppose that it has been determined that the $6,000 for a
> The estimated times (in weeks) and immediate predecessors for the activities in a project are given in the following table. Assume that the activity times are independent. (a). Calculate the expected time and variance for each activity. (b). What is th
> Dream Team Productions was in the final design phases of its new film, Killer Worms, to be released next summer. Market Wise, the firm hired to coordinate the release of Killer Worms toys, identified 16 critical tasks to be completed before the release o
> Getting a degree from a college or university can be a long and difficult task. Certain courses must be completed before other courses may be taken. Develop a network diagram in which every activity is a particular course that must be taken for a given d
> The Bender Construction Co. is involved in constructing municipal buildings and other structures that are used primarily by city and state municipalities. This requires developing legal documents, drafting feasibility studies, obtaining bond ratings, and
> Bowman Builders manufactures steel storage sheds for commercial use. Joe Bowman, president of Bowman Builders, is contemplating producing sheds for home use. The activities necessary to build an experimental model and related data are given in the follow
> General Foundry’s project crashing data are shown in Table 11.9. Crash this project to 13 weeks using CPM. What is the final time for each activity after crashing? Table 11.9: TIME (WEEKS) COST ($) CRASH COST CRITICAL АCTIVITY NORMA
> How can we determine the probability that a project will be completed by a certain date? What assumptions are made in this computation?
> Fred Ridgeway has been given the responsibility of managing a training and development program. He knows the earliest start time, the latest start time, and the total cost for each activity. This information is given in the following table: (a). Using e
> The air pollution project discussed in the chapter has progressed over the past several weeks, and it is now the end of week 8. Lester Harky would like to know the value of the work completed, the amount of any cost overruns or under runs for the project
> Using PERT, Ed Rose was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months and the project variance is 4. (a). What is the probability that the project will be completed in 17 months or les
> Tom Schriber, the director of personnel of Management Resources, Inc., is in the process of designing a program that its customers can use in the job-finding process. Some of the activities include preparing resumés, writing letters, making
> A project was planned using PERT with three time estimates. The expected completion time of the project was determined to be 40 weeks. The variance of the critical path is 9. (a). What is the probability that the project will be finished in 40 weeks or
> After consulting with Butch Radner, George Monohan was able to determine the activity times for constructing the weed-harvesting machine to be used on narrow rivers. George would like to determine ES, EF, LS, LF, and slack time for each activity. The tot
> Sid Davidson was able to determine the activity times for the leadership training program. He would like to determine the total project completion time and the critical path(s). The activity times appear in the following table (see Problem 11-12): ACTIV
> The integer programming problem below has been developed to help First National Bank decide where, out of 10 possible sites, to locate four new branch offices: Xi represents Winter Park, Maitland, Osceola, Downtown, South Orlando, Airport, Winter Garden,
> Mick Garcia, a certified financial planner (CFP), has been asked by a client to invest $250,000. This money may be placed in stocks, bonds, or a mutual fund in real estate. The expected return on investment is 13% for stocks, 8% for bonds, and 10% for re
> Major Bill Bligh, director of the Army War College’s new 6-month attaché training program, is concerned about how the 20 officers taking the course spend their precious time while in his charge. Major Bligh recognizes that there are 168 hours per week an
> If you were the president of the college you are attending and were employing goal programming to assist in decision making, what might your goals be? What kinds of constraints would you include in your model?
> Hilliard Electronics produces specially coded computer chips for laser surgery in 64MB, 256MB, and 512MB sizes. (1MB means that the chip holds 1 million bytes of information.) To produce a 64MB chip requires 8 hours of labor, a 256MB chip takes 13 hours,
> Solve Problem 10-21. Are any goals unachieved in this solution? Explain. Problem 10-21: Geraldine Shawhan is president of Shawhan File Works, a firm that manufactures two types of metal file cabinets. The demand for her two-drawer model is up to 600 cab
> Geraldine Shawhan is president of Shawhan File Works, a firm that manufactures two types of metal file cabinets. The demand for her two-drawer model is up to 600 cabinets per week; the demand for a three-drawer cabinet is limited to 400 per week. Shawhan
> The campaign manager for a politician who is running for reelection to a political office is planning the campaign. Four ways to advertise have been selected: TV ads, radio ads, billboards, and social media advertising buys. The costs of these are $900 f
> Triangle Utilities provides electricity for three cities. The company has four electric generators that are used to provide electricity. The main generator operates 24 hours per day, with an occasional shutdown for routine maintenance. Three other genera
> A real estate developer is considering three possible projects: a small apartment complex, a small shopping center, and a mini-warehouse. Each of these requires different funding over the next 2 years, and the net present values of the investments also v
> Innis Construction Company specializes in building moderately priced homes in Cincinnati, Ohio. Tom Innis has identified eight potential locations to construct new single-family dwellings, but he cannot put up homes on all of the sites because he has onl
> Horizon Wireless, a cellular telephone company, is expanding into a new era. Relay towers are necessary to provide wireless telephone coverage to the different areas of the city. A grid is superimposed on a map of the city to help determine where the tow
> An airline owns an aging fleet of Boeing 737 jet airplanes. It is considering a major purchase of up to 17 new Boeing model 787 and 767 jets. The decision must take into account numerous cost and capability factors, including the following: (1) the air
> Student Enterprises sells two sizes of wall posters, a large 3- by 4-foot poster and a smaller 2- by 3-foot poster. The profit earned from the sale of each large poster is $3; each smaller poster earns $2. The firm, although profitable, is not large; it
