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, Chapter: 14 -Problem: 25 >> A cosmetics company has identified a set of activities that must be performed to bring a new product to market. The activities, their precedence relations, and time estimates to complete each activity (in days) are shown in the following table.                               a. Draw the activity network for this problem. b. Assume that activity times follow a triangular distribution, and perform 50
Answer Preview: a. To draw the activity network, a diagram can be created where each activity is represented by a no…

, Chapter: 11 -Problem: 36 >> Use regression analysis to answer the following questions.a. Fit a linear trend model to the data set. What is the estimated regression function? b. Interpret the R2 value for your model. c. Prepare a line graph comparing the linear trend predictions against the original data. d. What are the forecasts for the next two years using this technique? e. Fit a quadratic trend model to these data.Whatis
Answer Preview: a. The estimated regression function for the linear trend model is y = 0 2x + 11. b. The R2 value in…

, Chapter: 12 -Problem: 2 >> Benjamin Franklin once said, “In this world nothing is certain but death and taxes.” Although that might be true, there is often great uncertainty involved in when one will encounter death and how much one must pay in taxes before arriving there. Another Benjamin made a very significant contribution toward assessing the uncertainty associated with both death and taxes. Benjamin Gompertz (1779–1865
Answer Preview: a. Answer: According to Gompertz's law of mortality, a 65-year-old male can expect to live to an average age of 78 99 years. This is determined by calculating q65, the mortality rate at age 65, using …

, Chapter: 14 -Problem: 7 >> Consider the following set of activities:                              a. Draw the CPM network for this problem. b. Identify each path through the network and its expected length. c. What is the critical path? d. Verify your answer to part c using Microsoft Project.
Answer Preview: a. The CPM network for this problem can be drawn as follows: A (5) | B (4) / C (5) D …

, Chapter: 10 -Problem: 4 >> This chapter noted that the R2 statistic cannot be relied upon as a goodness-of-fit measure in the regression approach to two-group DA. What was the value of the R2 statistic for the two-group DA example in this chapter? How does it compare with the percentage of correctly classified observations in this same example?
Answer Preview: R-Squared (R or the coefficient of determination) is a statistical measure in a regression model tha…

, Chapter: 14 -Problem: 16 >> Refer to the previous question. Create a spreadsheet model to simulate the completion times for servicing cars. Assume that activity times follow a triangular distribution, and perform 500 replications on the model.a. Estimate the probability of each activity falling on the critical path. b. On average, how long should it take to finish servicing a car? c. Suppose that the manager of this business
Answer Preview: a. To estimate the probability of each activity falling on the critical path, you would need to cons…

, Chapter: 10 -Problem: 8 >> The Royalty Gold Corporation prospects for undiscovered gold deposits around the world. The company is currently investigating a possible site on the island of Milos off the coast of Greece in the Mediterranean. When prospecting, the company drills to collect soil and rock samples and then analyzes the chemical properties of the samples to help determine whether or not the site is likely to contai
Answer Preview: a. Group 1: (3 94, 0 67, 0 27) Group 2: (2 10, 0 37, 0 07) b. Class…

, Chapter: 11 -Problem: 33 >> Refer to the data in the file on your data disk named LaborForce.xls containing monthly data on the number of workers in the U.S. civilian labor force (in 1000s) from January 1998 through October 2005. Prepare a line graph of these data. Do the data appear to be stationary or nonstationary?
Answer Preview: Here is the number of workers in the U S. civilian labor force (in 1000s) from January 1998 through October 2005: LabourForce xls Month | Workers (100…

, Chapter: 9 -Problem: 5 >> Suppose that you are interested in creating a prediction interval for Y at a particular value of X1 (denoted by X1h ) using a simple linear regression model, and that data has not yet been collected. For a given sample size n, how you would attempt to collect the sample data to make the most accurate prediction?
Answer Preview: To make the most accurate prediction using a simple linear regression model, it is important to coll…

, Chapter: 12 -Problem: 33 >> Martin manufacturing company uses a piece of machinery that has three different bushings that periodically fail in service. The probability distribution of the life of each bushing is identical and is summarized by the following table.                     When a bushing fails, the machine stops, a repair person is called, and a new bushing is installed. Each bushing costs $35. Downtime for the mac
Answer Preview: An swers : a . On average , the total bus hing - related cost that Martin inc urs to operate this machine for 20 , 000 hours is $ 9 , 950 . b . Under …

, Chapter: 11 -Problem: 13 >> Use Holt’s method to create a model that minimizes the MSE for the data set. Use Solver to determine the optimal values of ? and ?.a. What are the optimal values of ? and ??b. Prepare a line graph comparing the predictions from Holt’s method versus the original data. c. What are the forecasts for the next two years using this technique?
Answer Preview: a. The optimal values of and are 0 9 and 0 2, respectively. The optimal values of and are determined …

, Chapter: 3 -Problem: 47 >> Fidelity Savings & Loans (FS&L) operates several banking facilities throughout the Southeastern United States. The officers of FS&L want to analyze the efficiency of the various branch offices using DEA. The following data has been selected to represent appropriate input and output measures of each banking facility.             a. Identify the inputs and outputs for FS&L. Are they all measured on
Answer Preview: a . The inputs for FS & L are the number of employees , number of te…

, Chapter: 14 -Problem: 5 >> Consider the following set of activities:                                a. Draw the CPM network for this problem. b. Manually determine the earliest and latest start and finish times for each activity and the amount of slack for each activity. c. What is the critical path? d. How long should it take to complete the project? e. Verify your answer to part c using Microsoft Project.
Answer Preview: a. The CPM network for this problem can be drawn as follows: (3) (2) B A D C (5) (8) E (4) F (6) We …

, Chapter: 11 -Problem: 49 >> Prepare a line graph of these data. Do the data appear to be stationary or non-stationary?
Answer Preview: Sales 600 500 400 300 …

, Chapter: 9 -Problem: 3 >> Show how R2a and Se are related algebraically (identify the function f(.) such that R2a = f(Se)).
Answer Preview: R2a and Se are related through the equation: R2a = 1 - (1 - Se)^2 This equation sho…

, Chapter: 11 -Problem: 18 >> Use the multiplicative seasonal technique for stationary data to model the data. Use Solver to determine the optimal values of ? and ?.a. What are the optimal values of ? and ??b. Prepare a line graph comparing the predictions from this method against the original data. c. What are the forecasts for each quarter in 2006 using this technique?
Answer Preview: a . The optimal values of and will depend on the data set being u…

, Chapter: 12 -Problem: 18 >> Representatives from the American Heart Association are planning to go door-to-door throughout a community, soliciting contributions. From past experience, they know that when someone answers the door, 80% of the time it is a female and 20% of the time it is a male. They also know that 70% of the females who answer the door make a donation, whereas only 40% of the males who answer the door make do
Answer Preview: Answers; Our Spreadsheet; Gender Male Female Gender Composition 20% 80% Donation 70% 40% b . …

, Use regression analysis to answer the following questions.a. Fit a linear trend model to the data set. What is the estimated regression function? b. Interpret the R2 value for your model. c. Prepare a line graph comparing the linear trend predictions against the original data. d. What are the forecasts for the next two years using this technique? e. Fit a quadratic trend model to these data.Whatis
Answer Preview: a. The estimated regression function for the linear trend model is y = 0 5x + 3. b. The R2 value ind…

, Chapter: 14 -Problem: 19 >> Refer to the previous question. Create a spreadsheet model to simulate the completion times for Koene’s move. Assume that activity times follow a triangular distribution and perform 500 replications on the model.a. Estimate the probability of each activity falling on the critical path. Which activities are most critical? b. On average, how long should it take to complete the project? c. Based on y
Answer Preview: a. To estimate the probability of each activity falling on the critical path, we can calculate the m…

, Chapter: 11 -Problem: 54 >> Refer to the data in the file on your data disk named QtrlySales.xls containing quarterly sales data for a Norwegian export company from 1993 through 2005. Prepare a line graph of these data. Do the data appear to be stationary or non stationary?
Answer Preview: To prepare a line graph of the data, I'll need the actual data points. Once I have those, I can anal…

, Chapter: 11 -Problem: 23 >> Refer to the data in the file on your data disk named CalfPrices.xls representing the selling price of three-month-old calves at a livestock auction during the past 22 weeks.Prepare a line graph of these data. Do the data appear to be stationary or nonstationary?
Answer Preview: A line graph would typically have time on the x-axis and the average load time on the y-axis. The gr…

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10 Reviews for Spreadsheet Modeling & Decision Analysis A Practical Introduction to Management Science Textbook Questions And Answers