The table below displays a forecast partial completed using double exponential smoothing (Holt's) method. a b tau 0.5 0.4 1 2 Demand intercept slope Holt's Ft,t+tau t Dt St G Ft,t+1 Ft,t+2 1 16 16.00 0.00 16.00 16.00 2 20 18.00 0.80 18.80 19.60 3 25 21.90 2.04 23.94 25.98 4 30 26.97 3.25 30.22 33.47 5 32 S5 G5 F5,6 F5,7 a) Use Double Exponential Smoothing (Holt's) method to update Sg and G5. b) Calculate F5,6 and F5,7. What does F5,7 represent? Use plain English to explain this notation