Sales of vegetable dehydrators at Bud Banis's dis- count department store in St. Louis over the past year are shown below. Management 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 2009-2010 Unit Sales Management's Forecast July 100 August 93 September 96 October 110 November 124 December 119 January 92 February 83 March 101 120 April 96 114 May 89 110 June 108 108

a) Compute MAD and MAPE for management's technique.

b) Do management's results outperform (i.e., have smaller MAD and MAPE than) a naive forecast?

c) Which forecast do you recommend, based on lower forecast error?