Using simple exponential smoothing and the following time series data, respond to each of the items. B. Click here for the Excel Data File Required: a. Compute all possible forecasts using a smoothing coefficient () of 0.8 . Note: Negative amounts should be indicated by a minus sign. Round your answers to 2 decimal places. b. Based on the MAD, what is the error associated with period 11's forecast? Note: Round your answer to 2 decimal places. c. Based on the MAPE, what is the percent error associated with period 11's forecast? Note: Round your answer to 2 decimal places