Sales of Volkswagen's popular Beetle have grown steadily at auto dealerships in Nevada during the past 5 years (see table below). a) Forecasted sales for year 6 using a 3-year moving average is sales (round your response to one decimal place). b) The MAD for a 3-year moving average based forecast is sales (round your response to one decimal place). c) The MSE for a 3-year moving average based forecast is sales (round your response to the nearest whole number)