4. Wicker Widget Works (WWW), manufacturer of the world famous Western White Widget (W3), would like to build a forecasting system to assist in production planning and inventory control. Demand for the past 6 months is shown below. Month Sales Jan 100 Feb 90 Mar 95 Apr 100 May 105 Jun 95 (a) Develop a forecast for July using (i) a simple exponential smoothing model with = 0.20, (ii) a simple exponential smoothing model with a = 0.50, and (iii) a 3-month moving average.