a. What is the difference between moving average and weighted moving average? Using four periods data for January, February, March and April as 100, 104, 95, 99 find the moving average and a weighted moving average (choose the weights yourself) for the month of May. b. Sales of a telephone answering machine for the last three years are given below: i. Find the seasonal index for each of the months. ii. Find the least square regression line y=a+bx; where b=xi2nx2yinxy;a=ybx; iii. Draw the regression line found in ii) iv. Using the regression equation determine 3rd year demand and show it in the graph. v. Forecast the rounded-off monthly demand for each of the months