Please do the following problems 19 and 21 Problems on Moving Averages Problems
ID: 3128300 • Letter: P
Question
Please do the following problems
19 and 21 Problems on Moving Averages Problems 16 through 21 are based on the following data. Observations of the demand for a certain part stocked at a parts supply depot during the calendar year 2013 were Month Demand Month Demand January February March April May June 89 57 144 221 223 286 212 275 188 312 July September October November December 280 16. Determine the one-step-ahcad forecasts for the demand for January 2014 using 17. Using a four-month moving average, determine the one-step-ahead forecasts for 18. Using a four-month moving average, determine the two-step-ahead forecast for July 3-, 6-, and 12-month moving averages July through December 2013 through December 2013. (Hint: The two-step-ahead forecast for July is based on the observed demands in February through May.) 19. Compute the MAD for the forecasts obtained in Problems 17and 18. Which method gave better results? Based on forecasting theory, which method should have given better results? 20. Compute the one-step-ahead three-month and six-month moving-average forecasts for July through December. What effect does increasing N from 3 to 6 have on the forecasts? 21. What would an MA(I) forecasting method mean? Compare the accuracy of MA(I) and MA(4) forecasts for July through December 2013
Explanation / Answer
Solution (16): One-step ahead forecast for demand 3, 6 and 12-month moving average forecast for January, 2014.
(17) One step ahead moving average forecast for four month (July through December, 2013)
(18) Two-step four month moving average forecast for July to December, 2013.
Month Demand 3 Month moving average 6 Month moving average 12 Month moving average January 89 February 57 March 144 April 221 96.66666667 May 177 140.6666667 June 280 180.6666667 July 223 226 161.3333333 August 286 226.6666667 183.6666667 September 212 263 221.8333333 October 275 240.3333333 233.1666667 November 188 257.6666667 242.1666667 December 312 225 244 258.3333333 249.3333333 205.3333333