Principles Of Operations Management
11th Edition
ISBN: 9780135173930
Author: RENDER, Barry, HEIZER, Jay, Munson, Chuck
Publisher: Pearson,
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Chapter 4, Problem 40P
Summary Introduction
To compute: A seasonalized or adjusted sales
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Since the beginning of the year, the purchase manager at a department store has
been recording sales data to be used to compute 4-period moving averages to
forecast sales for an upcoming month. Sales data for the months of January through
September are reported in the table below.
Month
January
February
March
April
May
June
July
August
September
Sales
21
20
39
22
29
14
42
28
27
Computed forecast values are not rounded.
Compute the four-period moving average forecast for October.
value as a whole number by rounding.
Specify the
Compute the mean absolute deviation (MAD) for the four-period moving average
forecasts.
Specify the MAD as a whole number by rounding.
Compute the mean squared error (MSE) for the four-period moving average
forecasts. Specify the MSE as a whole number by rounding.
Compute the mean absolute percentage error (MAPE) for the four-period moving
average forecasts.
Specify the MAPE as a whole number by rounding.
CHECK ANSWER
Phillip Cane, the managing editor of Your Life Magazine, needs to develop a forecasting system for monthly newsstand sales in order to schedule press runs. Sales in thousands of copies for the last eight months of 2020 (the first year of publication) were:
Month (2020) Sales
May 50
June 45
July 60
August 52
September 69
October 60
November 47
December 53
Phillip does not believe there is a seasonal pattern. Make the forecast using the following techniques for the first six months of 2021:
Exponential smoothing with α = 0.4
Ordinary least squares technique or linear regression analysis
Make graphical presentations of your answers and determine which…
3) Seasonality: The following data represent dinner sales at a busy restaurant. Use linear
regression to predict sales for each day of week 5 and the total sales for week 5. Estimate the
percentage of weekly sales that occur over the weekend (include Friday, Saturday, and
Sunday). Finally, determine which days of the week are increasing and decreasing in sales, using
the slopes of the LR lines.
Week
Mon
Wed
Fri
Sat
Sun
Tue
177
170
Thu
190
Total
270
152
180
321
386
166
218
203
402
427
167
333
357
229
3
158
170
170
205
163
173
158
225
349
433
212
a) Graph the seasonal data and attach the graph to this page.
b) Determine the slope for each day of the week.
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Total
Slope
c) Estimate the percentage of weekend sales in week 5:
d) For which day are sales increasing the fastest?
e) For which day are sales decreasing the fastest?
Chapter 4 Solutions
Principles Of Operations Management
Ch. 4 - Ethical Dilemma We live in a society obsessed with...Ch. 4 - What is a qualitative forecasting model, and when...Ch. 4 - Identify and briefly describe the two general...Ch. 4 - Identify the three forecasting time horizons....Ch. 4 - Briefly describe the steps that are used to...Ch. 4 - A skeptical manager asks what medium-range...Ch. 4 - Explain why such forecasting devices as moving...Ch. 4 - What is the basic difference between a weighted...Ch. 4 - What three methods are used to determine the...Ch. 4 - Research and briefly describe the Delphi...
Ch. 4 - What is the primary difference between a...Ch. 4 - Define time series.Ch. 4 - What effect does the value of the smoothing...Ch. 4 - Explain the value of seasonal indices in...Ch. 4 - Prob. 14DQCh. 4 - In your own words, explain adaptive forecasting.Ch. 4 - Prob. 16DQCh. 4 - Explain, in your own words, the meaning of the...Ch. 4 - Prob. 18DQCh. 4 - Give examples of industries that are affected by...Ch. 4 - Prob. 20DQCh. 4 - Prob. 21DQCh. 4 - CEO John Goodale, at Southern Illinois Power and...Ch. 4 - The following gives the number of pints of type B...Ch. 4 - a) Plot the above data on a graph. Do you observe...Ch. 4 - Refer to Problem 4.2. Develop a forecast for years...Ch. 4 - A check-processing center uses exponential...Ch. 4 - The Carbondale Hospital is considering the...Ch. 4 - The monthly sales for Yazici Batteries, Inc., were...Ch. 4 - Prob. 7PCh. 4 - Daily high temperatures in St. Louis for the last...Ch. 4 - Lenovo uses the ZX-81 chip in some of its laptop...Ch. 4 - Data collected on the yearly registrations for a...Ch. 4 - Use exponential smoothing with a smoothing...Ch. 4 - Prob. 12PCh. 4 - At you can see in the following table, demand for...Ch. 4 - Prob. 14PCh. 4 - Refer to Solved Problem 4.1 on page 144. a) Use a...Ch. 4 - Prob. 16PCh. 4 - Prob. 17PCh. 4 - Prob. 18PCh. 4 - Income at the architectural firm Spraggins and...Ch. 4 - Resolve Problem 4.19 with = .1 and =.8. Using...Ch. 4 - Prob. 21PCh. 4 - Refer to Problem 4.21. Complete the trend-adjusted...Ch. 4 - Prob. 23PCh. 4 - The following gives the number of accidents that...Ch. 4 - In the past, Peter Kelles tire dealership in Baton...Ch. 4 - George Kyparisis owns a company that manufactures...Ch. 4 - Attendance at Orlandos newest Disneylike...Ch. 4 - Prob. 28PCh. 4 - The number of disk drives (in millions) made at a...Ch. 4 - Prob. 30PCh. 4 - Emergency calls to the 911 system of Durham, North...Ch. 4 - Using the 911 call data in Problem 4.31, forecast...Ch. 4 - Storrs Cycles has just started selling the new...Ch. 4 - Prob. 35PCh. 4 - Prob. 36PCh. 4 - Prob. 37PCh. 4 - Prob. 38PCh. 4 - Prob. 39PCh. 4 - Prob. 40PCh. 4 - Prob. 41PCh. 4 - Prob. 42PCh. 4 - Mark Gershon, owner of a musical instrument...Ch. 4 - Prob. 44PCh. 4 - Cafe Michigans manager, Gary Stark, suspects that...Ch. 4 - Prob. 46PCh. 4 - The number of auto accidents in Athens, Ohio, is...Ch. 4 - Rhonda Clark, a Slippery Rock, Pennsylvania, real...Ch. 4 - Accountants at the Tucson firm, Larry Youdelman,...Ch. 4 - Prob. 50PCh. 4 - Using the data in Problem 4.30, apply linear...Ch. 4 - Bus and subway ridership for the summer months in...Ch. 4 - Prob. 53PCh. 4 - Dave Fletcher, the general manager of North...Ch. 4 - Prob. 55PCh. 4 - Prob. 56PCh. 4 - Prob. 57PCh. 4 - Sales of tablet computers at Ted Glickmans...Ch. 4 - The following are monthly actual and forecast...Ch. 4 - Prob. 1CSCh. 4 - Prob. 2CSCh. 4 - Prob. 3CSCh. 4 - Prob. 1.1VCCh. 4 - Prob. 1.2VCCh. 4 - Using Perezs multiple-regression model, what would...Ch. 4 - Prob. 1.4VCCh. 4 - Prob. 2.1VCCh. 4 - Prob. 2.2VCCh. 4 - Prob. 2.3VCCh. 4 - Prob. 2.4VCCh. 4 - Prob. 2.5VC
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