Question

Since populations are continuously changing based on their immediate previous state, the
Pert formula can be used to quickly estimate near future growth (or decay). Assume that the
1990 census for a city of 800,000 reveals an annual increase of 2.3%, estimate the population
for the year 2000.

How long will it take for the population to reach 1 million? You must show your algebraic
work

Answer 1

A=Pe^rt=800,000e^(.023*10)=1,006,880 in year 2000

How long to one million?
1,000,000=800,000e^(.023t)
1.25=e^(.023t) take ln of each side
.233=.023t
t=9.7 years

Answer 2

Never heard A=Pe^rt referred to as the "Pert" formula, but it makes perfect sense.

I guess I am never too old to learn.