Question: A toy company buys large quantities of plastic pellets for use in the manufacture of its products. The production manager wants to develop a forecasting system for plastic pellet prices. The price per pound of plastic pellets has varied as shown:
|
Month
|
Plastic Pellets Price/Pound
|
Month
|
Plastic Pellets Price/Pound
|
|
1
|
$0.39
|
9
|
$0.35
|
|
2
|
$0.41
|
10
|
$0.38
|
|
3
|
$0.45
|
11
|
$0.39
|
|
4
|
$0.44
|
12
|
$0.43
|
|
5
|
$0.40
|
13
|
$0.37
|
|
6
|
$0.41
|
14
|
$0.38
|
|
7
|
$0.38
|
15
|
$0.36
|
|
8
|
$0.36
|
16
|
$0.39
|
Provide your forecast for Month 17 using the moving average, weighted moving average, and exponential smoothing methods as follows:
a) For the moving average, use a 4-period moving average.
b) Use a three-period weighted moving average. Unfortunately, you spilled water on the sheet with the weights to be used for the weighted moving average and this blurred the weight for the third most recent period. However, you can tell that the weights for the first and second most recent months are 0.65 and 0.25 respectively.
c) For exponential smoothing, use an a = 0.25, and the forecast for Month 7 is $0.41.
d) Using the methods in a) through c), which method provides the better forecast for Month 17? Why? Your selection criteria must be based on the forecasts for Months 11 through 16 using one of the one of the numerical evaluation methods we have learned and used on homework assignments this term.
Provide your forecasts to three decimal places ($0.xxx).