The population of a region is growing exponentially. There were 15 million people in 1980 (when $t=0$) and 70 million people in 1990. Find an exponential model for the population (in millions of people) at any time $t$, in years after 1980.
(Note: if you use decimal approximations for the numerical constants in your work, be sure to retain enough significant figures through your work to ensure that subsequent answers are correct.)
$P(t)$=
What population do you predict for the year 2000?
Predicted population in the year 2000 = million people.
What is the doubling time?
Doubling time = years.