please help me do this in excel

a) Compute seasonal indices for each quarter based on a CMA b) Deseasonalize the data and develop a trend line on the deseasonalized data c) Use the trend line to forecast the sales for each quarter of year 4 . d) Use the seasonal indices to adjust the forecasts found in part c. e) Run regression using deseasonalized sales and time to get trend to obtain the final forecasts for periods, 13,14,15,16 Ploweses Trend and Seasonality Sensonal Indexes \begin{tabular}{|c|cccc|} \hline Quarter & 1 & 2 & 3 & 4 \\ \hline & & & \\ \hline & & & \\ \hline Averege & & & \\ \hline \end{tabular} Forecast Projoction for yoar 4 Trend Model: T= \begin{tabular}{|llll|l|} \hline Year Quarter & 1 & Trend Forecast Seasonal index & Quliterty Forscast \\ \hline & & \end{tabular} Forecast Projection for year