Quick Homework Help

# the population of a certain town doubled after 20 years of steady growth. What was the growth rate over those 20 years? ⚑ Flag

by Bobby186 at April 24, 2011

Bobby -The problem doesn't state, but let's assume the growth rate is "continuous" over the 20 years.  The formula for continuous growth is:, whereg(t) = population after t yearsP=initial populationr=ratet=timeNow simply fill in the values provided in the problem:2 = Now take the natural log of both sides:ln(2) = 20r ; now solve for r:r = ln (2) / 20I'll leave the math for you.Hope that helped

Steve204 April 24, 2011

P(t)=Poe^rt where P(t) is the population when time is t and Po is the population when t=0  r is the rate.2=1e^20rsolve for r

chitra003 April 24, 2011

look it up in the marhs section there is a very similar questio to yours.

Haneefah April 24, 2011

Answer: P(t)=Poe^rt where P(t) is the population when time is t and Po is the population when t=0 r is the rate.2=1e^20rsolve for r

...sydnie... April 24, 2011

the rule of 70 states that the time it takes for a population to double is equivalent to 70/x where x is the growth rate. so all you do is 70/x=20 and get 3.5 for x meaning growth rate is 3.5%

GURUKID April 25, 2011