Let P (t) = 20000 (1.04)^t be the population of a town t years after the year 2000.

Question

How will I estimate for example the population reaches 25000... how do I know which year it will become 25000?

Answer 1

20000(1.04)^t = 25000

(1.04)^t = 1.25

log(1.04)^t = log1.25

t(log1.04) = log1.25

t = log1.25 / log1.04 = 5.689 years after 2000