the population of the united states can be modeled by the function p(x) = 80.21e^0.131x where x is the number of decades (ten year periods) since 1900 and is the population in millions. a. graph p(x) over the interval 0 lower or equal to x and lower or equal to 15. b. if the population of the united states continues to grow at this rate, predict the population in the years 2010 and 2020.