please solve question

(a) Calculate the trend a1=nxi2(xi)2nxiyixiyi (b) Calculate the seasonal components (c) Apply linear regression on the four trend points for year 2011 only. ae=nyia1nxi=ya1x \begin{tabular}{|l|l|l|l|l|} \hline Year & Quarter & Sales & 4-quratermovingaverage & Trend \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline & & & & \\ \hline \end{tabular} The sales figures for a business are shown below