Observations of the demand for certain part stocked at a parts supply depot during the calendar year 1999 were.
|
Month
|
Demand
|
Month
|
Demand
|
|
Jan
|
95
|
July
|
220
|
|
Feb
|
65
|
Aug
|
300
|
|
Mar
|
140
|
Sept
|
230
|
|
Apr
|
200
|
Oct
|
285
|
|
May
|
165
|
Nov
|
195
|
|
June
|
285
|
Dec
|
320
|
1. Determine the one-step-ahead forecasts for the demand for January 2000 using 3-, 6-, and 12 -month moving averages.
2. Using a five-month moving average, determine the one-step-ahead forecasts for July through February 2000.
3. Using a five-month moving average, determine the two-step-ahead forecasts for July through February 2000.
4. Compute the MAD for the forecasts obtained in (b) and (c). Which method gave better results? Based on forecasting theory, which method should have given better results?