Given the series of demand data below DpictureClick here for the Excel Data File a. Calculate the forecasts for periods 7 through 11 using moving average models with n=2,n=4, and n=6. (Round your intermediate calculations and final answers to 1 decimal place.) b-1. Calculate the bias and MAD for each set of forecasts. (Negative answers should be indicated by a minus sign. Round your intermediate calculations and final answers to 1 decimal place.) b-1. Calculate the bias and MAD for each set of forecasts. (Negative answers should be indicated by a minus sign. Round your intermediate calculations and final answers to 1 decimal place.)