A particular forecasting model was used to forecast a six$-$month period. Here are the forecasts and actual demands that resulted:

$\backslash$table$[[,$FORECAST,ACTUAL$],[$April$,256,206],[$May$,330,248],[$June$,406,323],[$July$,355,306],[$August$,380,332],[$September$,456,407]]$

a$.$ Find the tracking signal for each month. $($Negative values should be indicated by a minus sign. Round your answers to the nearest whole number.$)$

$\backslash$table$[[$Month$,$Tracking Signal$],[$April$,],[$May$,],[$June$,],[$July$,],[$August$,],[$September$,]]$

b$.$ Does the model used here give acceptable answers?

No$,$ the model's performance is poor.

Yes, the model's performance is good.