Suppose That We Calculate the Four-Period Moving Average of the Following

Multiple Choice

Suppose that we calculate the four-period moving average of the following time series $$\begin{array} { | c | c c c c | c | c | } \hline \boldsymbol { t } & 1 & 2 & 3 & 4 & 5 & 6 \\\hline \boldsymbol { y } _ { \mathbf { t } } & 16 & 28 & 21 & 15 & 26 & 12 \\\hline\end{array}$$ The centered moving average for period 3 is:

A) 22.5
B) 21.25
C) 20.50
D) 18.5