| tD | Van Everdigen and Hurst Exact Solution for (PD) | Homotopy Analysis Method (PD) | Absolute Error |
| 1500 | 4.061 | 4.000 | 0.061 |
| 2000 | 4.205 | 4.200 | 0.005 |
| 2500 | 4.317 | 4.300 | 0.017 |
| 3500 | 4.498 | 4.478 | 0.020 |
| 4000 | 4.552 | 4.548 | 0.004 |
| 5000 | 4.663 | 4.655 | 0.008 |
| 6000 | 4.754 | 4.750 | 0.004 |
| 7000 | 4.829 | 4.820 | 0.009 |
| 9000 | 4.949 | 5.042 | 0.093 |
| 10,000 | 4.996 | 5.100 | 0.104 |
| 12,000 | 5.072 | 5.180 | 0.108 |