HELP PLEASE!!!

Problem $3-23($Algo$)$

After using your forecasting model for six months, you decide to test it using a tracking signal. Here are the forecast and actual demands for the six$-$month period:

$\backslash$table$[[$PERIOD$,$FORECAST,ACTUAL$],[$May$,450,495],[$June$,500,545],[$July$,550,395],[$August$.,615,460],[$September$,635,675],[$October$,710,625]]$

Find the tracking signal.

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

$\backslash$table$[[$Period$,$Tracking Signal$],[$May$,],[$June$,],[$July$,],[$August$,],[$September$,],[$October$,]]$