The following are monthly actual and forecast demand levels for May through December for units of a product manufactured by the Deborah Bishop Company in Des Moines:

$\backslash$table$[[$Month$,$Actual Demand,Forecast Demand$],[$May$,108,100],[$June$,78,100],[$July$,108,97],[$August$,115,101],[$September$,108,100],[$October$,110,104],[$November$,120,102],[$December$,115,107]]$

For the given forecast, the tracking signal $=$ MADs $($round your response to two decimal places$).$