5. Time-series Analysis (9 points) a. (3 points) A company wants to forecast demand using the simple moving average. If the company uses four prior yearly sales values (i.e., year 2005= 157 , year 2006=136, year 2007=103, and year 2008=178 ), what is the 4 -year simple moving average forecast for year 2009 ? b. ( 3 points) A company wants to forecast demand using the weighted moving average. If the company uses three prior yearly sales values (i.e., year 2006= 195, year 2007=167 and year 2008=194 ), and we want to weight year 2006 at 16%, year 2007 at 33% and year 2008 at the remaining percentage, what is the weighted moving average forecast for year 2009 ? c. (3 points) A company has had actual unit demand for four consecutive years of 100,110,125, and 150 . The respective forecasts using exponential smoothing were 120 for each of the four years. What value of alpha, the smoothing constant, was the firm using? For the fifth year, however, the forecast is 140 . What value of alpha is the firm using for the fifth year? 6. Forecasting Comparison ( 4 points) a. (2 points) Briefly explain why MAD (mean absolute deviation) is used to evaluate forecasting performance instead of mean deviation? b. (2 points) A company has actual unit demand for three consecutive years of 104, 200, and 150. The respective forecasts for the same three years are 163 , 114, and 154. What is the resutting MAD value that can be computed from this data