the final answer please

A manager has been using a certain forecasting technique to forecast demand for word processing units for the past five periods. Actuat and forecasted amounts are shown below. He had difficulties in identifying whether the used technique is better than the weighted moving average (WMA) with 0.5 being the weight with the most recent, 0.3, 0.2. Calculate the MAD for the manager's forecast? (Note: write the answer as a number with 2 decimal places only, e.g. 12.50.55.83 , 12.00) Period Demand Forecasted 90 98 2 85 95 92 5 1 87 91 3 4 7 88 95