Consider the Quarterly Production Data (In Thousands of Units)for the XYZ

Essay

Consider the quarterly production data (in thousands of units)for the XYZ manufacturing company below. $$\begin{array} { l c c c } & { \text { Year } } \\\text { Quarter } & 1998 & 1999 & 2000 \\\text { Winter } & 9 & 21 & 25 \\\text { Spring } & 16 & 20 & 27 \\\text { Summer } & 16 & 30 & 34 \\\text { Fall } & 17 & 23 & 32\end{array}$$
-Calculate the 4 period (quarter)centered moving average for the entire time series.