A manager has been using a certain technique to forecast demand for project man- agement software at her store. Actual demand and her corresponding predictions are shown below:

a. What was the manager's forecast error for April?

b. What was the manager's forecast percent error for July?

c. What are the mean error, the mean squared error, the mean absolute deviation, the mean absolute percent error, and the tracking signal for these 5 months of forecasting?

d. If the manager had used a 3-month moving average instead of her technique, what would have been her forecast for June? What would have been her percent error?

e. If the manager had used simple exponential smoothing with a = 0.2 instead of her technique, what would the forecast for August be, assuming that simple exponential smoothing had produced a perfectly accurate forecast in March?

Month Actual Demand Manager's Forecast March 45 45 April 42 50 May 34 45 June 48 40 July 38 45