Consider the Following Time Series with Forecast Values and Errors

Multiple Choice

Consider the following time series with forecast values and errors.
$$\begin{array} { | l | l | } \hline \begin{array} { l } \text { Actual } \\\text { Demand }\end{array} & \begin{array} { l } \text { Forecast } \\\text { Demand }\end{array} \\\hline 10 & 9 \\\hline 13 & 15 \\\hline 15 & 16 \\\hline 11 & 13 \\\hline 12 & 10 \\\hline\end{array}$$
-Calculate the mean square deviation (MSD) .

A) 2.8
B) 13.4
C) 7.5
D) 1.6
E) 2.4