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: Year Jan Feb Mar April May Jun Jul Aug Sep 1 185 180 190 200 210 2 190 170 190 198 225 3 188 172 192 200 220 Oct 215 205 200 195 190 215 200 204 195 215 195 216 198 202 196 217 201 Nov Dec 188 186 185 190 i. Find the seasonal index for each of the months. ii. Find the least square regression line y = a + bx; where b xx-x.y x-nx a=y-b.x; iii. Draw the regression line found in ii) iv. V. Using the regression equation determine 3rd year demand and show it in the graph. Forecast the rounded-off monthly demand for each of the months.