The population of the United States from 1790 to 1860 is given by the following formula, where t is years since 1790 and N is the population, in millions.
N = 3.93 x 1.03t

(a) What was the population in 1790?
million

(b) Express the population in 1820 using functional notation.
N( )

(c) Calculate the value of the population in 1820. (Round your answer to two decimal places.)
million