Enclosed you will find the instructions for my exercise and work in excel. Item 12 says estimate the demand for a baby diapers in the clinic for period 25 for each model. I did it but I think, it is incorrect. I emailed the professor and the only answer I received from him was "

Since demand for period 25 is not yet known, the forecasting error cannot be calculated.

Therefore, the model comparison can only be made through period 24.

Forecast for period 25 is to be obtained using the same formula you employed to estimate demand for all other periods. but If you check I used for three methods a different formula. Could you let me know how can I calculate the period 25? Thank and look forward to hearing from you.

Maternity Clinic Diaper Competitive Data Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Diaper Consumption (48-unit bags) 163 258 356 262 300 339 299 293 360 237 262 340 411 296 486 317 443 449 414 424 561 576 622 547 585 Mean Absolute Deviation Mean Square Error NAVE FORESCAST 262 300 339 299 293 360 237 262 340 411 296 486 317 443 449 414 424 561 576 622 547 MAD MSE Absolute Forescast Square Error Error 38 39 40 6 67 123 25 78 71 115 190 169 126 6 35 10 137 15 46 75 38 1,444 1,521 1,600 36 4,489 15,129 625 6,084 5,041 13,225 36,100 28,561 15,876 36 1,225 100 18,769 225 2,116 5,625 1,406 69 7,583 SINGLE AVERAGE FORESCAST 260 268 280 282 284 292 287 284 289 298 298 311 311 319 326 331 335 346 357 368 376 Absolute Forescast Error 40 71 19 11 76 55 25 56 122 2 188 6 132 130 88 93 226 230 265 179 209 Square Error 1,620 5,069 374 112 5,814 3,049 610 3,085 14,864 6 35,237 38 17,375 16,915 7,715 8,688 50,873 52,812 70,418 31,979 43,629 106 3 Period Moving Average Forescast 292 306 300 313 310 317 297 286 280 338 349 398 366 415 403 435 429 466 520 586 582 Absolute Forescast Square Error Error 8 33 1 20 50 80 35 54 131 42 137 81 77 34 11 11 132 110 102 39 3 64 1,089 2 387 2,467 6,453 1,202 2,880 17,248 1,736 18,769 6,507 5,878 1,133 121 128 17,424 12,027 10,336 1,547 8 57 17,632 5,370