A county's population in 1991 was 147 million. In 1998 it was 153 million. Estimate the population in 2017 using the exponential growth formula. Round your answer to the nearest million.

Let t=number of years since 1991.

Then

P (t) = 147 e^ (kt) ... in millions

P (0) = 147 e^ (0) = 147

P (7) = 147 e^ (7k) = 153

e^ (7k) = (153/147)

take ln both sides

ln (e^ (7k)) = ln (153/147)

7k=0.0400 = > k=0.005715

Year 2017=>t=2017-1991=26

P (26) = 147e^ (26*.005715) = 170.55

Answer: in 2017, the projected population is 170.55 millions.