Problem $3-21($Algo$)$

The following table shows predicted product demand using your particular forecasting method along with the actual demand that occurred:

$\backslash$table$[[$FORECAST$,$ACTUAL$],[1,490,1,540],[1,390,1,490],[1,690,1,590],[1,742,1,640],[1,790,1,690]]$

Compute the tracking signal using the mean absolute deviation and running sum of forecast errors.

Note: Negative values should be indicated by a minus sign. Round your "Mean Absolute Deviation", "Tracking Signal" to $2$ decimal places and all other answers to the nearest whole number.

$\backslash$table$[[$Period$,$Forecast,Actual,Deviation,RSFE,$\backslash$table$[[$Absolute$],[$Deviation$]],\backslash$table$[[$Sum of$],[$Absolute$],[$Deviation$]],$MAD,TS$],[1,1,490,1,540,,,,,,],[2,1,390,1,490,,,,,,],[3,1,690,1,590,,,,,+,],[4,1,742,1,640,,,,,,],[5,1,790,1,690,,,,,,]]$