Question

A marketing manager is forecasting the sales of cars per week. Determine the error for each of the following forecasts. Then, calculate MAD and MSE. Period Value Forecast Error 1 202 — — 2 191 202 3 173 192 4 169 181 5 171 174 6 175 172 7 182 174 8 196 179 9 204 189 10 219 198 11 227 211

Answer 1

period	value	Forecast	error	|error|	error^2
1	202
2	191	202	-11	11	121
3	173	192	-19	19	361
4	169	181	-12	12	144
5	171	174	-3	3	9
6	175	172	3	3	9
7	182	174	8	8	64
8	196	179	17	17	289
9	204	189	15	15	225
10	219	198	21	21	441
11	227	211	16	16	256
			average	12.50	191.90

from above : error for each of forecast is given in error column

MAD =12.50

MSE =191.90