A time series with forecast values is presented in the following table: $$\begin{array} { | r | r | r | }
\hline \text { Month } & \text { Aolual. } & \text { Foracafl } \
\hline J an & a & \
\hline \text { Mar } & 12 a & 1.1 a \
\hline \text { May } & 1.15 a & 1.2 a \
\hline J u l& 1.25 a & 12.21 a \
\hline \mathrm { Sep } & 1.3 a & 1.25 a \
\hline
\end{array}$$ On this table, a is some nondisclosed value.The mean square error (MSE)is ______% of a.
A)4.15
B)0.415
C)4.15a
D)0.415a
E)0.00332

Question

A time series with forecast values is presented in the following table: $$\begin{array} { | r | r | r | } 
\hline \text { Month } & \text { Aolual. } & \text { Foracafl } \
\hline J an & a & \
\hline \text { Mar } & 12 a & 1.1 a \
\hline \text { May } & 1.15 a & 1.2 a \
\hline J u l& 1.25 a & 12.21 a \
\hline \mathrm { Sep } & 1.3 a & 1.25 a \
\hline
\end{array}$$ On this table, a is some nondisclosed value.The mean square error (MSE)is ______% of a.
A)4.15
B)0.415
C)4.15a
D)0.415a
E)0.00332

Quizplus · Accepted Answer

The MSE is calculated as the average of the squared differences between actual and forecast values. Here, the differences are $0.9a$, $0.05a$, $10.96a$, and $0.05a$. Squaring these and averaging gives $0.415a^2$, which is $0.415\%$ of $a^2$.

A Time Series with Forecast Values Is Presented in the Following