Excel Online Structured Activity: Moving Average Forecast period moving average forecast and answer the following questions. \begin{tabular}{|c|} \hline E21 \\ 1 \\ 2 \\ 3 \\ 4 \\ 5 \\ 6 \\ 7 \\ 8 \\ 9 \\ 10 \\ 11 \\ 12 \\ 13 \\ 14 \\ 15 \\ 16 \\ 17 \\ 18 \\ 19 \\ 20 \\ 21 \\ \hline 22 \\ 23 \\ 24 \\ 25 \\ \hline \end{tabular}