| LINE | A | B | C | D |
| 1 | Jennifer | Smith | . | . |
| 2 | Problem | Demo | . | . |
| 3 | P | .4 | . | . |
| 4 | . | . | . | . |
| 5 | Period | Enrollment | Prediction | Deviation |
| 6 | 1 | 2400 | 2400 | = abs (b6 - c6) |
| 7 | =A6+1 | 2350 | =$b$3*b6 + (1-$b$3)*c6 | . |
| 8 | . | 2290 | . | . |
| 9 | . | 2380 | . | . |
| 10 | . | 2415 | . | . |
| 11 | . | 2405 | . | . |
| 12 | . | 2370 | . | . |
| 13 | . | 2340 | . | . |
| 14 | . | 2390 | . | . |
| 15 | . | 2410 | . | . |
| 16 | . | 2375 | . | . |
| 17 | . | 2350 | . | . |
| 18 | . | 2395 | . | . |
| 19 | . | 2420 | . | . |
| 20 | . | . | Total Absolute Deviation |
=sum(d6:d19) |
| 21 | . | . | Mean Absolute Deviation |
=d20/a19 |
Copy the formulas in columns A, C and D down through line 19.