How do I predict the population growth in 2050 with this problem?

Question

Starting from a 2013 population of 7.1 billion, use the current annual growth rate of the United States, which is about 0.70%, to
(a) find the approximate doubling time (use the rule of 70)

100 years

and to
(b) predict world population in 2050.

____billion

 

I figured out part a using the doubling time formula, but what formula do I use to find the population prediction in 2050?

 

Answer 1

You can use the future value formula. We use it in finance to calculate the future value of an investment amount. Here it is.

 

Future Value (FV)=Present Value x (1+Rate)^n

 

FV = 7.1billion x (1+0.007)^37