math calculus (please help me)
posted by jam .
In 1970, the total enrollment in public universities and colleges in a country was 5.1 million students. By 2004, enrollment had risen to 14.3 million students. Assume enrollment can be modeled by exponential growth.
(a) Estimate the total enrollments in 1980, 1990, and 2000. (Round your answers to one decimal place.)
(b) How many years after 1970 until the enrollment doubles from the 2004 figure? (Round your answer to one decimal place.)
(c) By what percent is the enrollment increasing each year? (Round your answer to two decimal places.)
Let the mathematical model be
where x=years past 1970.
f(x)=population in millions
Note: much better accuracy is obtained by shifting the origin to 1970, the closest possible.
Substituting given data for 1970:
The complete model is then
to find the estimated population for 1980, etc.