\begin{tabular}{|l|c|} \hline Month & Actual Sales (Pairs of reading glasses) \\ \hline January 2021 & 2800 \\ \hline February 2021 & 3000 \\ \hline March 2021 & 5000 \\ \hline April 2021 & 4000 \\ \hline May 2021 & 5600 \\ \hline June 2021 & 8000 \\ \hline July 2021 & 8000 \\ \hline August 2021 & 7900 \\ \hline September 2021 & 6000 \\ \hline October 2021 & 4050 \\ \hline November 2021 & 4900 \\ \hline December 2021 & 5 \\ \hline \end{tabular} a. The linear regression equation of the sales of reading glasses for the 2021 financial year is given by the expression: y=201.4x+4091 (where ' y ' denotes monthly sales, and ' x ', the number representing the month. For example, x=1,2,3, etc., if the month is January, February, March, etc.). Use the regression equation to determine the Mean Absolute Deviation (MAD) of the regression forecasts for the April - December 2021 period. (5 marks) b. Which of the two methods is better at forecasting the sales of the reading classes? Explain. (2 marks) \begin{tabular}{|l|c|} \hline Month & Actual Sales (Pairs of reading glasses) \\ \hline January 2021 & 2800 \\ \hline February 2021 & 3000 \\ \hline March 2021 & 5000 \\ \hline April 2021 & 4000 \\ \hline May 2021 & 5600 \\ \hline June 2021 & 8000 \\ \hline July 2021 & 8000 \\ \hline August 2021 & 7900 \\ \hline September 2021 & 6000 \\ \hline October 2021 & 4050 \\ \hline November 2021 & 4900 \\ \hline December 2021 & 5 \\ \hline \end{tabular} a. The linear regression equation of the sales of reading glasses for the 2021 financial year is given by the expression: y=201.4x+4091 (where ' y ' denotes monthly sales, and ' x ', the number representing the month. For example, x=1,2,3, etc., if the month is January, February, March, etc.). Use the regression equation to determine the Mean Absolute Deviation (MAD) of the regression forecasts for the April - December 2021 period. (5 marks) b. Which of the two methods is better at forecasting the sales of the reading classes? Explain. (2 marks)