Foreign-Born Population.
In 1970, only 4.7% of the U.S. population was foreign-born, while in 2007, 12.6% of the population was foreign-born (Sources: Annual Social and Economic Supplements, Current Population Surveys, U.S. Census Bureau, U.S. Department of Commerce). The quartic function
f (x) = -0.0000007623221x4 + 0.00021189064x3
- 0.016314058x2 + 0.2440779643x
+ 13.59260684,
where x is the number of years since 1900, can be used to estimate the percent of the U.S. population for years 1900 to 2007 that was foreign-born. Using this function, estimate the percent of the population that was foreign-born in 1930, in 1990, and in 2000?