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

FORECAST ACTUAL

April $258208$

May $332250$

June $407327$

July $357308$

August $382334$

September $457397$

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.$)$