| | Fair Play, MO | Mount Vernon, MO | United States |
| Population | 610 | 4,470 | 329,725,481 |
| Female Population | 50.2% | 53.1% | 50.5% |
| Male Population | 49.8% | 46.9% | 49.5% |
| Median Age | 47.1 | 43.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 475 | 4,564 | 309,327,143 |
| Population - 2000 | 418 | 4,017 | 285,036,114 |
| Population - 1990 | 442 | 3,726 | 251,960,433 |
| Pop. 2000 to Now | 16.8% | 11.5% | 15.6% |
| Pop. 1990 to Now | 10.4% | 20.2% | 30.8% |
| space4 | | | |
| Population Density | 1,498.8 | 1,124.5 | 93.4 |
| Land Area | 0.4 | 4.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Fair Play, MO | Mount Vernon, MO | United States |
| Age 0 to 4 | 3.3% | 4.4% | 5.9% |
| Age 5 to 9 | 5.7% | 6.9% | 6.1% |
| Age 10 to 14 | 10.0% | 5.5% | 6.6% |
| Age 15 to 17 | 1.3% | 2.6% | 3.9% |
| Age 18 to 20 | 4.4% | 2.8% | 4.0% |
| Age 21 to 24 | 3.8% | 4.0% | 5.2% |
| Age 25 to 34 | 8.0% | 11.0% | 13.8% |
| Age 35 to 44 | 9.5% | 13.2% | 12.9% |
| Age 45 to 54 | 21.5% | 14.0% | 12.6% |
| Age 55 to 59 | 8.0% | 4.0% | 6.7% |
| Age 60 to 64 | 11.1% | 7.2% | 6.3% |
| Age 65 to 74 | 4.3% | 11.6% | 9.6% |
| Age 75 to 84 | 6.6% | 6.9% | 4.5% |
| Age 85 and over | 2.5% | 5.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Fair Play, MO | Mount Vernon, MO | United States |
| White | 98.5% | 92.0% | 59.4% |
| Black | 0.0% | 0.8% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.5% | 2.3% | 3.2% |
| Hispanic | 1.0% | 5.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Fair Play, MO | Mount Vernon, MO | United States |
| Married Population | 49.2% | 47.3% | 49.8% |
| Currently Married | 44.7% | 43.6% | 48.0% |
| Married but Separated | 4.5% | 3.7% | 1.8% |
| Single Population | 50.8% | 52.7% | 50.2% |
| Never Married | 15.0% | 22.4% | 33.8% |
| Divorced | 25.9% | 15.7% | 10.8% |
| Widowed | 9.9% | 14.6% | 5.6% |
| space5 | | | |
| Household Size | 2.36 | 2.19 | 2.60 |
| Households | 259 | 1,863 | 124,010,992 |
| Family Households | 174 | 925 | 80,755,759 |
| Married couple, w/children | 37.9% | 29.7% | 30.5% |
| Married couple, no children | 30.5% | 44.3% | 42.9% |
| Non Family Households | 85 | 938 | 43,255,233 |
| Single householder, w/children | 25.9% | 18.6% | 15.8% |
| Single householder, no children | 5.7% | 7.4% | 10.8% |