Was this using the Holt's method? The equations are different in your spreadsheet than the ones we are to use. I've attached a picture of the equations since the answers I have are different and I'm not sure why.

V F (Smooth Forecast) C D E F G H I K L M N 0.8 0.2 F (Smooth Forecast) T (Trend) FIT (Total) FIT, = FT. FIT,+ a(A,-1 - FIT,-;) TI-1 + B(F, - FIT,-1) Ft = FIT -1 + a(At-1 - FIT,-1) T. = Ti-1 + B(F, - FIT,-1) FIT, is the forecast including trend at period t (this period). F, is the forecast at period t (this period). T, is the trend estimate at period t (this period). FIT,-1 is the forecast including trend at period t-1 (perivous period). F-1 is the forecast at period t-1 (previous period). T,-1 is the trend estimate at period t-1 (previous period). A,-1 is the actual data at period t-1(previous period). a is exponential smoothing constant. B is trend smoothing constant