. Monthly demand for figures at a car company are as follows: Weights Oldest 25% Next oldest 35% Newest 40% Month Demand January 4250 February 3782 March 5160 April 10405 May 12383 June 14287 July 11766 August 13154 September 7150 October 6552 November 5232 December 5198

a) Estimate demand for the next 3 months using a 3-month weighted moving average and a simple exponential smoothing with a=0.1

b) Compare the performance of simple exponential smoothing with a = 0.1 and a = 0.9. What difference in forecasts do you observe? Which of the two smoothing constants do you prefer and why?

c) Evaluate MAD, MAPE, MSE, bias, and TS in each case