In Dry Country the yield of barley was as follows: Put NA if the answer is not applicable. 1986 1987 20 30 1988 60 1989 1990 45 30 a) Determine the moving average of length 3. F1991 = F1992 = b) Determine the exponential smoothing forecast for the years 1988 to 1992 with a=0.5 for the barley of Dry Country. Assume that the forecast was 59 for year 1988. F1988 F1989 = F1990 F1991 F1992