答案是6.9%
| Balance | ||||
| Year | Yearly return | Yearly withdrawal | 1000000 | Principal |
| 1 | 6.9 | 50000 | 1019000 | 1000000 |
| 2 | 6.9 | 51500 | 1037811 | Yearly inflation |
| 3 | 6.9 | 53045 | 1056375 | 3% |
| 4 | 6.9 | 54636 | 1074628 | |
| 5 | 6.9 | 56275 | 1092502 | |
| 6 | 6.9 | 57964 | 1109921 | |
| 7 | 6.9 | 59703 | 1126803 | |
| 8 | 6.9 | 61494 | 1143059 | |
| 9 | 6.9 | 63339 | 1158592 | |
| 10 | 6.9 | 65239 | 1173296 | |
| 11 | 6.9 | 67196 | 1187057 | |
| 12 | 6.9 | 69212 | 1199753 | |
| 13 | 6.9 | 71288 | 1211248 | |
| 14 | 6.9 | 73427 | 1221397 | |
| 15 | 6.9 | 75629 | 1230044 | |
| 16 | 6.9 | 77898 | 1237018 | |
| 17 | 6.9 | 80235 | 1242137 | |
| 18 | 6.9 | 82642 | 1245203 | |
| 19 | 6.9 | 85122 | 1246000 | |
| 20 | 6.9 | 87675 | 1244299 | |
| 21 | 6.9 | 90306 | 1239850 | |
| 22 | 6.9 | 93015 | 1232385 | |
| 23 | 6.9 | 95805 | 1221614 | |
| 24 | 6.9 | 98679 | 1207226 | |
| 25 | 6.9 | 101640 | 1188885 | |
| 26 | 6.9 | 104689 | 1166229 | |
| 27 | 6.9 | 107830 | 1138869 | |
| 28 | 6.9 | 111064 | 1106387 | |
| 29 | 6.9 | 114396 | 1068331 | |
| 30 | 6.9 | 117828 | 1024218 |