| | Syosset, NY | Prosper, TX | United States |
| Population | 19,347 | 28,825 | 329,725,481 |
| Female Population | 49.1% | 49.0% | 50.5% |
| Male Population | 50.9% | 51.0% | 49.5% |
| Median Age | 43.2 | 35.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 18,905 | 9,744 | 309,327,143 |
| Population - 2000 | 18,544 | 2,097 | 285,036,114 |
| Population - 1990 | 18,967 | 1,018 | 251,960,433 |
| Pop. 2000 to Now | 5.8% | 1,185.5% | 15.6% |
| Pop. 1990 to Now | 3.4% | 2,548.0% | 30.8% |
| space4 | | | |
| Population Density | 3,888.8 | 1,146.6 | 93.4 |
| Land Area | 5.0 | 25.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Syosset, NY | Prosper, TX | United States |
| Age 0 to 4 | 3.2% | 8.2% | 5.9% |
| Age 5 to 9 | 6.8% | 11.0% | 6.1% |
| Age 10 to 14 | 10.4% | 10.5% | 6.6% |
| Age 15 to 17 | 7.7% | 5.8% | 3.9% |
| Age 18 to 20 | 1.6% | 3.8% | 4.0% |
| Age 21 to 24 | 3.9% | 1.8% | 5.2% |
| Age 25 to 34 | 7.4% | 8.7% | 13.8% |
| Age 35 to 44 | 11.6% | 17.8% | 12.9% |
| Age 45 to 54 | 18.6% | 17.8% | 12.6% |
| Age 55 to 59 | 6.5% | 4.7% | 6.7% |
| Age 60 to 64 | 6.1% | 2.7% | 6.3% |
| Age 65 to 74 | 10.6% | 4.6% | 9.6% |
| Age 75 to 84 | 3.6% | 2.0% | 4.5% |
| Age 85 and over | 1.8% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Syosset, NY | Prosper, TX | United States |
| White | 63.9% | 69.5% | 59.4% |
| Black | 1.0% | 10.1% | 12.2% |
| Asian | 29.1% | 7.0% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.5% | 0.3% | 0.4% |
| Two or More Races | 1.4% | 3.1% | 3.2% |
| Hispanic | 4.0% | 9.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Syosset, NY | Prosper, TX | United States |
| Married Population | 66.2% | 71.9% | 49.8% |
| Currently Married | 65.6% | 71.6% | 48.0% |
| Married but Separated | 0.6% | 0.3% | 1.8% |
| Single Population | 33.8% | 28.1% | 50.2% |
| Never Married | 27.1% | 20.0% | 33.8% |
| Divorced | 3.2% | 6.4% | 10.8% |
| Widowed | 3.6% | 1.7% | 5.6% |
| space5 | | | |
| Household Size | 3.09 | 3.45 | 2.60 |
| Households | 6,204 | 8,365 | 124,010,992 |
| Family Households | 5,235 | 7,654 | 80,755,759 |
| Married couple, w/children | 52.7% | 59.9% | 30.5% |
| Married couple, no children | 39.5% | 31.8% | 42.9% |
| Non Family Households | 969 | 711 | 43,255,233 |
| Single householder, w/children | 2.8% | 6.6% | 15.8% |
| Single householder, no children | 5.0% | 1.6% | 10.8% |