Questions and Answers of Statistics for Management

Repeat the experiment calculating the sample variances (Excel function VAR). If the sample variance is an unbiased estimator of the population variance, what value should be observed when you
Repeat the experiment calculating the sample medians. (Use Excel function MEDIAN.) If the sample median is an unbiased estimator of the population mean, what should you expect when you calculate the
Repeat Exercise 9.6 calculating the sampling distribution of the sample variance.In exercise 9.6Refer to Exercise 9.5. In exercise 9.5Repeat the simulation described earlier with the following
Refer to Exercise 9.6.In exercise 9.6Refer to Exercise 9.5. In exercise 9.5Repeat the simulation described earlier with the following changes. At step 3, specify 1 for the Number of Variables and
Refer to Exercise 9.5. In exercise 9.5Repeat the simulation described earlier with the following changes. At step 3, specify 1 for the Number of Variables and 10000 for the Number of Random Numbers.
Repeat the simulation described earlier with the following changes. At step 3, specify 1 for the Number of Variables and 10000 for the Number of Random Numbers. At step 4, change the distribution to
Repeat the simulation using the sample size n = 10. Draw the histogram using bins 1.0, 1.5, 2.0, . . . 6.0. Compare this histogram with the one you created in Exercise 9.1. Describe the differences
Because of the high cost of hospital stays, anything that can reduce their length and the costs of medication would be appreciated by insurance companies, hospitals, and patients. A physician
Scrabble is one of the oldest and most popular board games. It is played all over the world, and there is even an annual world championship competition. The game is played by forming words and
Repeat the experiment calculating the following for each sample. The Excel function that produces this statistic is VARP. Calculate the mean of these statistics. Discuss why we define the sample
Refer to Exercise 9.3.? In exercise 9.3 Repeat the simulation using the sample size n = 10. Draw the histogram using bins 1.0, 1.5, 2.0, . . . 6.0. Compare this histogram with the one you created in
Calculate the mean and standard deviation of the sample means stored in Column C. These are the mean and standard deviation of the simulated sampling distribution. Are they close to the theoretical
Draw the histogram of the sample means using bins 1.0, 1.5, 2.0, . . . 6.0. Does it appear to be bell shaped? Explain.
You have decided to invest in a portfolio made up of these four stocks: Bank of Nova Scotia (BNS),Canadian National Railway (CNR), Canadian Tire (CTC.A), and Magna International (MG). You have also
Provide two examples of production processes and their associated chance variation.
The high price of gasoline is likely to lead to less travel. An economist specializing in energy uses wanted to learn more about driving habits, and, in particular, distances traveled by cars, buses,
A major movie studio has just completed its latest epic, a musical comedy about the life of Attila the Hun. Because the movie is different (no sex or violence), the studio is uncertain about how to
The Megabuck Computer Company is thinking of introducing two new products. The first, Model 101, is a small computer designed specifically for children between ages 8 and 16. The second, Model 202,
Max the Bookie is trying to decide how many telephones to install in his new bookmaking operation. Because of heavy police activity, he cannot increase or decrease the number of telephones once he
Suppose that in Exercise 22.39 a sample of size 5 showed that only one person believes the new ad. In light of this additional information, what should the manager do?In exercise 22.39Credibility is
Suppose that in Exercise 22.39 it is possible to perform a survey to determine the percentage of people who believe the ad. What would a sample of size 1 be worth?In exercise 22.39Credibility is
Credibility is often the most effective feature of an advertising campaign. Suppose that, for a particular advertisement, 32% of people surveyed currently believe what the ad claims. A marketing
The president of an automobile battery company must decide which one of three new types of batteries to produce. The fixed and variable costs of each battery are shown in the accompanying table.The
Suppose that in Exercise 22.32 a random sample of 25 radio listeners revealed that 2 people would be regular listeners of the station. What is the optimal decision now?In exercise 22.32A radio
In Exercise 22.32, suppose that it is possible to survey radio listeners to determine whether they would tune in to the station if the format changed to rock and roll. What would a survey of size 2
Suppose that in Exercise 22.14 a consultant offers to analyze the problem and predict the amount of electricity required by the new community. To induce the electric company to hire her, the
Repeat Exercise 22.33, given that 12 out of 100 households respond affirmatively.In exercise 22.33There is a garbage crisis in North America—too much garbage and no place to put it. As a
There is a garbage crisis in North America—too much garbage and no place to put it. As a consequence, the idea of recycling has become quite popular. A waste-management company in a large city is
A radio station that currently directs its programming toward middle age listeners is contemplating switching to rock-and-roll music. After analyzing advertising revenues and operating costs, the
To improve her decision-making capability, the electronics products manufacturer in Exercise 22.16 performs a survey of potential buyers of compact disc players. She describes the product to 25
What is the maximum price the electronics product manufacturer should be willing to pay for perfect information regarding the market share in Exercise 22.16?In exercise 22.16An international
A sporting-goods storeowner has the opportunity to purchase a lot of 50,000 footballs for $100,000. He believes that he can sell some or all by taking out mail-order advertisements in a magazine.
What conclusions can you draw about the effect of the prior probabilities on EVSI from Exercises 22.25–22.27?
Repeat Exercise 22.25 with the following prior probabilities.P(s1) = .90 P(s2) = .05 P(s3) = .05In exercise 22.25Given the following payoff table, prior probabilities, and likelihood probabilities,
Repeat Exercise 22.25 with the following prior probabilities.P(s1) = .5 P(s2) = .4 P(s3) = .1In exercise 22.25Given the following payoff table, prior probabilities, and likelihood probabilities, find
Given the following payoff table, prior probabilities, and likelihood probabilities, find the expected value of sample information.Payoff TablePrior probabilitiesLikelihood Probabilities az a, 60 90
With the accompanying payoff table and the prior and posterior probabilities computed in Exercise 22.23 calculate the following.a. The optimal act for each experimental outcomeb. The expected value
Calculate the posterior probabilities from the prior and likelihood probabilities that follow.Prior ProbabilitiesP(s1) = .5 P(s2) = .5Likelihood Probabilities .98 .02 .05 .95 S2
Determine the posterior probabilities, given the following prior and likelihood probabilities.Prior probabilitiesP(s1) = .25 P(s2) = .40 P(s3) = .35Likelihood Probabilities .25 30
What conclusion can you draw about the effect of the probabilities on EVPI from Exercises 22.19 and 22.20?
Redo Exercise 22.19, changing the probabilities to the following values.a. P(s1) = .75 P(s2) = .25b. P(s1) = .95 P(s2) = .05In exercise 22.19Given the following payoff table and probabilities,
Given the following payoff table and probabilities, determine EVPI.P(s1) = .5 P(s2) = .5 az az a4 a1 45 30 65 20 110 70 95 S2
For Exercise 22.17, determine the opportunity loss table and compute EOL*. Confirm that EOL* = EVPI.In exercise 22.17Find EPPI, EMV*, and EVPI for the accompanying payoff table and probabilities. a,
Find EPPI, EMV*, and EVPI for the accompanying payoff table and probabilities.P(s1) = .10 P(s2) = .25 P(s3) = .50 P(s4) = .15 a, аз 75 60 110 S2 40 110 150 220 120 85 S3 250 120 130 S4
An international manufacturer of electronic products is contemplating introducing a new type of compact disk player. After some analysis of the market, the president of the company concludes that,
A retailer buys bushels of mushrooms for $2 each and sells them for $5 each. The quality of the mushrooms begins to decline after the first day they are offered for sale; therefore, to sell the
The electric company is in the process of building a new power plant. There is some uncertainty regarding the size of the plant to be built. If the community that the plant will service attracts a
A building contractor must decide how many mountain cabins to build in the ski resort area of Chickoh- pee. He builds each cabin at a cost of $26,000 and sells each for $33,000. All cabins unsold
Refer to Exercise 22.11. The owner has assigned the following probabilities:P(Demand = 100) = .2, P(Demand = 150) = .25,P(Demand = 200) = .40, P(Demand = 250) = .15Find the EMV decision.In exercise
The owner of a clothing store must decide how many men’s shirts to order for the new season. For a particular type of shirt, she must order in quantities of 100 shirts. If she orders 100 shirts,
Refer to Exercise 22.9. Using subjective assessments the manager has assigned the following probabilities to the number of snowfalls. Determine the optimal decision.P(0) = .05 P(1) = .15 P(2) = .30
The manager of a large shopping center in Buffalo is in the process of deciding on the type of snow clearing service to hire for his parking lot. Two services are available. The White Christmas
Refer to Exercise 22.7. Assume that the probability of each value of demand is the same for all possible demands.a. Determine the EMV decision.b. Determine the EOL decision.In exercise 22.7A baker
A baker must decide how many specialty cakes to bake each morning. From past experience, she knows that the daily demand for cakes ranges from 0 to 3. Each cake costs $3.00 to produce and sells for
If we assign the following probabilities to the states of nature in Exercise 22.5, determine the EOL decision:P(s1) = .2 P(s2) = .6 P(s3) = .2
Refer to Exercise 22.4. Set up the opportunity loss table.In exercise 22.4Given the following payoff table, draw the decision tree: аз -1 4 10 S1 S2 S3 20 -10
Given the following payoff table, draw the decision tree: аз -1 4 10 S1 S2 S3 20 -10
If we assign the following probabilities to the states of nature in Exercise 22.1, determine the EMV decision:P(s1) = .4 P(s2) = .1 P(s3) = .3 P(s4) = .2
Draw the decision tree for Exercise 22.1.In exercise 22.1Set up the opportunity loss table from the following payoff table: 26 55 38 43 S2 43 29 $3 51 15 54
Set up the opportunity loss table from the following payoff table: 26 55 38 43 S2 43 29 $3 51 15 54
Optical scanners are used in all supermarkets to speed the checkout process. Whenever the scanner fails to read the bar code on the product, the cashier is required to manually punch the code into
A courier delivery company advertises that it guarantees delivery by noon the following day. The statistical process control plan calls for sampling 2,000 deliveries each day to ensure that the
A company that manufactures batteries employs statistical process control to ensure that its product functions properly. The sampling plan for the D-cell batteries calls for samples of 500 batteries
The Woods worth Publishing Company produces millions of books containing hundreds of millions of pages each year. To ensure the quality of the printed page, Woods worth uses statistical process
A plant produces 1,000 cordless telephones daily. A random sample of 100 telephones is inspected each day. After 30 days, the following number of defectives were found. Construct a p chart to
Raytheon of Canada Limited produces printed circuit boards (PCBs), which involve a number of soldering operations. At the end of the process, the PCBs are tested to determine whether they work
Random samples of 200 copier machines were taken on an assembly line every hour for the past 25 hours. The number of defective machines is shown here. Are there any points beyond the control limits?
To ensure that a manufacturing process is under control, 40 samples of size 1,000 were drawn, and the number of defectives in each sample was counted. The mean sample proportion was .035. Compute the
Calculate the process capability index for Exercise 21.34. Does the value of this index indicate that the production process is poor? Explain.In exercise 21.34The seats for the F-150 series Ford
If the specification limits for the plastic pipes in Exercise 21.40 are LSL = 2.9 inches and USL = 3.1inches, determine the process capability index Cpk.In exercise 21.40Plastic pipe is used for
Plastic pipe is used for plumbing in almost all new homes. If the pipes are too narrow or too wide, they will not connect properly with other parts of the plumbing system. A manufacturer of 3-inch
Almost all computer hardware and software producers offer a toll-free telephone number to solve problems associated with their products. The ability to work quickly to resolve difficulties is
Motor oil is packaged and sold in plastic bottles. The bottles are often handled quite roughly in delivery to the stores (bottles are packed in boxes, which are stacked to conserve truck space), in
Refer to Exercise 21.35. Nuts and bolts are used in the assembly of the transmission oil coolers. They are supposed to be tightened by a torque wrench to 7 foot-pounds with specification limits LSL =
Find the process capability index for Exercise 21.35.In exercise 21.35Long Manufacturing produces heat exchangers, primarily for the automotive industry. One such product, a transmission oil cooler,
Long Manufacturing produces heat exchangers, primarily for the automotive industry. One such product, a transmission oil cooler, is used in the cooling of bus transmissions. It is composed of a
The seats for the F-150 series Ford trucks are manufactured by Lear Seating. The frames must be 1, 496 mm wide with specification limits LSL = 1, 486 mm and USL = 1, 506 mm. Frames that are wider
The degree to which nuts and bolts are tightened in numerous places on a car is often important. For example, in Toyota cars, a nut holds the rear signal light. If the nut is not tightened
Lear Seating of Kitchener, Ontario, produces seats for Cadillacs and other GM cars and trucks. The Cadillac seat includes a part called the EK headrest. The frame of the headrest is made from steel
Refer to Exercise 21.30. If the lower and upper specification limits are 995 c and 1005 cc, respectively, what is Cpk?In exercise 21.30KW Paints is a company that manufactures various kinds of
KW Paints is a company that manufactures various kinds of paints and sells them in 1- and 4-liter cans. The cans are filled on an assembly line with an automatic valve regulating the amount of paint.
Refer to Exercise 21.28. Find the process capability index Cpk.In exercise 21.28An arc extinguishing unit (AEU) is used in the high-voltage electrical industry to eliminate the occurrence of
An arc extinguishing unit (AEU) is used in the high-voltage electrical industry to eliminate the occurrence of electrical flash from one live 25,000-volt switch contact to another. A small but
The fence of a saw is set so that it automatically cuts 2-by-4 boards into 96-inch lengths needed to produce prefabricated homes. To ensure that the lumber is cut properly, three pieces of wood are
Thirty samples of size 4 were drawn from a production process.a. Construct an S chart.b. Construct an x chart.c. Do the charts allow you to conclude that the process is under control?d. If the
Twenty-five samples of size 4 were taken from a production process. The sample means are listed in chronological order below. The mean of the sample means and the pooled standard deviation are
On average how many units will be produced until the control chart signals that the process is out of control when it is under control?A firm that manufactures notebook computers uses statistical
The operations manager is unsatisfied with the current sampling plan. He changes it to samples of size 2 every half hour. What is the average number of units produced until the chart indicates that
Refer to Exercise 21.10. Find the average run length to detect the shift.A production facility produces 100 units per hour and uses an x chart to monitor its quality. The control limits are set at 3
The number of housing starts (in 1,000s) in the northeast United States for the years 2004 to 2009 were recorded.a. Use the 2004–2008 data to calculate the seasonal indexes.b. Use the indexes and
Using the seasonal indexes and trend line, forecast revenues for the next four quarters.The revenues (in $millions) of a chain of ice cream stores are listed for each quarter during the previous 5
Determine the seasonal indexes. The revenues (in $millions) of a chain of ice cream stores are listed for each quarter during the previous 5 years. Year Quarter 2012 16 25 31 24 2015 18 29 45 24
Use regression analysis to determine the trend line.The revenues (in $millions) of a chain of ice cream stores are listed for each quarter during the previous 5 years. Year Quarter 2012 16 25 31 24
Discuss why exponential smoothing is not recommended as a forecasting tool in this problem.The revenues (in $millions) of a chain of ice cream stores are listed for each quarter during the previous 5
Plot the time series.The revenues (in $millions) of a chain of ice cream stores are listed for each quarter during the previous 5 years. Year Quarter 2012 16 25 31 24 2015 18 29 45 24 2016 2013 14 27
Apply the trend line and seasonal indexes from Exercise 20.29 to forecast accounts receivable for the next four quarters.In exercise 20.29A manufacturer of ski equipment is in the process of
Refer to Exercise 20.28. Use the seasonal indexes and trend line to forecast the number of pizzas to be sold for each of the next 7 days.In exercise 20.28The owner of a pizzeria wants to forecast the
Use the seasonal indexes and trend line from Exercise 20.27 to forecast the number of cable subscribers for the next four quarters.In exercise 20.27The number of cable television subscribers has
Refer to Exercise 20.26. Forecast next year’s merchandise trade balance using the following methods.a. Autoregressive forecasting model.b. Exponential smoothing method with w = .7.In exercise
Refer to Exercise 20.25. Forecast next year€™s enrollment using the following methods.a. Autoregressive forecasting model.b. Exponential smoothing method with w = .5.In exercise

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