Acountry's population in 1992 was 72 million. in 1998 it was 76 million. estimate the population in 2012 using the exponential growth formula. round your answer to the nearest million.

formual: p=ae^kt

We assume the annual percentage increase is the same. We will work out the constant k using the formula

We have
P = 76
A = 72
t = 6 years (from 1992 to 1998)

Substitute into the formula


Take log both sides give




We can now work out the number of population by the end of 2012 using the formula

We have
A = 72 million
k = 0.009
t = 10 years (1992 to 2012)

≈79 million