Question

The population of a region is growing exponentially. There were 40 million people in 1990 (t = 0) and 70 million in 2000. Find an expression for the population at any time t, in years. Use the general exponential function and remember to use exact values.

P(t)= (in millions)

- What population would you predict for the year 2010?

- What is the doubling time? (Round your answer to one decimal place.)

Answer 1

Now to find the general exponential function, we need to find out some information.
P(t)= Po x R^t
Where: P= total population
Po=initial population
R= rate
t= no of years after 1990

Answer 2

We have the current info:
P= 70 000 000
Po= 40 000 000
R=?
t= 2000-1990=10years

Answer 3

So sub the info into the equation to find the R.