The Chief Meteorologist Quit in a Huff One Afternoon and the Station

Essay

The chief meteorologist quit in a huff one afternoon and the station manager turned to a demented walrus to prepare the forecast for the following nine days during sweeps week. The walrus was a ratings hit, but his forecasts, displayed in the table below, were not entirely accurate. Calculate MAD, MAPE and a tracking signal for the forecasts.
$$\begin{array} { | c | c | c | } \hline \text { Period } & \text { Actual } & \text { Forecast } \\\hline 1 & 26 & 12 \\\hline 2 & 7 & 23 \\\hline 3 & 12 & 4 \\\hline 4 & 20 & 19 \\\hline 5 & 27 & 22 \\\hline 6 & 14 & 8 \\\hline 7 & 10 & 28 \\\hline 8 & 27 & 10 \\\hline 9 & 27 & 26 \\\hline\end{array}$$