Question

Pretend the world's population in 1987 was 4.5 billion and that the projection for 2016 is 8 billion.

What annual rate of growth is assumed in this prediction?

Answer 1

@kropot72 Can you help?

Answer 2

I got it! 1.98% per year

Answer 3

We can use the following equation to model the growth:
\[\large P=P _{i}(1+r)^{t}\]
where P is the population after t years, Pi is the initial population, and r is the annual rate of growth.
Putting the given values into the equation we get:
\[\large 8=4.5(1+r)^{29}\ ..........(1)\]
Now you need to solve (1) to find the value of r.