forecasts and actual demands that resulted:

$\backslash$table$[[,$FORECAST,ACTUAL$],[$April$,252,228],[$May$,327,302],[$June$,402,451],[$July$,352,423],[$August$,378,478],[$September$,452,503]]$

a$.$ Find the tracking signal for each month.

Note: Negative values should be indicated by a minus sign. Round your answers to $2$ decimal places.

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

b$.$ Is the model being used giving acceptable answers?

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

Yes, the model's performance is good.