(a) Given the data below, develop a forecast for the periods 4-6 using a three-period weighted moving average and weights of .5, .3, and 2. (3 marks) Actual Demand Period 1 123456 2 3 4 5 1 123 6 (b) If the actual demand was the following (see below), using the measures discussed in class determine the forecast accuracy measures. Is the forecast accurate? (5 marks) Actual Demand Period 19 20 18 19 17 2 3 19 20 18 19 17 E 4 5 6 (c) What does the a in the exponential smoothing formula represent? What is it? How does the value of a impact the forecast? When would you use a high value versus a low value? (4 marks) 22