Respond to each of the Items using the following time series data. Period Demand 20 46 20 9 17 19 34 39 Click here for the Excel Data File b. Compute all possible forecasts using exponential smoothing with a smoothing coefficient (o) of 0.3. (Negative amounts should be Indicated by a minus sign. Round your answers to 3 decimal places.) Period Demand Exponential Absolute Error Smooth Error 1 20 2 48 20 9 17 19 11 12 13 14 27 15