# Devry university-supply chain decision tools week 1 homework

Homework

Complete the following problems from Chapter 4 in your textbook. The Homework Problems grading rubric is posted in Doc Sharing—refer to the Homework Problems Rubric document.

Chapter 4 Problems

Problem 4.2 a, b, and c

Problem 4.6 a, b, and c

Problem 4.9 a, b, c, and d • a)Plot the above data on a graph. Do you observe any trend, cycles, or random variations?
• b)Starting in year 4 and going to year 12, forecast demand using a 3-year moving average. Plot your forecast on the same graph as the original data.
• c)Starting in year 4 and going to year 12, forecast demand using a 3-year moving average with weights of .1, .3, and .6, using .6 for the most recent year. Plot this forecast on the same graph.
• d)As you compare forecasts with the original data, which seems to give the better results?

The monthly sales for Yazici Batteries, Inc., were as follows:

 MONTH SALES January 20 February 21 March 15 April 14 May 13 June 16 July 17 August 18 September 20 October 20 November 21 December 23
• a)Plot the monthly sales data.
• b)Forecast January sales using each of the following:
• i)Naive method.
• ii)A 3-month moving average.
• iii)A 6-month weighted average using .1, .1, .1, .2, .2, and .3, with the heaviest weights applied to the most recent months.
• iv)Exponential smoothing using an α = .3 and a September forecast of 18.
• v)A trend projection.
• c)With the data given, which method would allow you to forecast next March’s sales?

•• 4.9

Lenovo uses the ZX-81 chip in some of its laptop computers. The prices for the chip during the past 12 months were as follows:

 MONTH PRICE PERCHIP MONTH PRICE PERCHIP January \$1.80 July 1.80 February 1.67 August 1.83 March 1.70 September 1.70 April 1.85 October 1.65 May 1.90 November 1.70 June 1.87 December 1.75
• a)Use a 2-month moving average on all the data and plot the averages and the prices.
• b)Use a 3-month moving average and add the 3-month plot to the graph created in part (a).
• c)Which is better (using the mean absolute deviation): the 2-month average or the 3-month average?
• d)Compute the forecasts for each month using exponential smoothing, with an initial forecast for January of \$1.80. Use α = .1, then α = .3, and finally α = .5. Using MAD, which a is the best?