The following tabulations are actual sales of units for six months and a starting forecast in January.

$\backslash$table$[[,$ACTUAL,FORECAST$],[$January$,100,85],[$February$,96,],[$March$,103,],[$April$,82,],[$May$,66,],[$June$,90,]]$

a$.$ Calculate forecasts for the remaining five months using simple exponential smoothing with $a=0\mathrm{.}4.$

$\backslash$table$[[,$Forecasts$],[$February$,],[$March$,],[$April$,],[$May$,],[$June$,]]$

b$.$ Calculate the Mean Absolute Deviation for all the forecasts, including January's.

Note: Round your answer to $1$ decimal place.

Mean absolute deviation