Sales of vegetable dehydrators at Bud Banis discount department store in St.Louis over the past year are shown below. Managment prepared a forecast using a combination of exponential smoothing and its collective judgment for the 4 months. (March, April, May and June of 2010):
Month 09-10 Unit sales Management Forecast
July 100
August 93
Sept 96
Oct 110
Nov 124
Dec 119
Jan 92
Feb 83
March 101 120
April 96 114
May 89 110
June 108 108
a) Compute the MAD and MAPE for management's technique.
b) Do management's results outperform a naive forecast?
c) Which forecast do you recommend, based on lower forecast error?