A population is counted at 100 individuals in 1998.In 2006,a new count found 1,600 individuals.The doubling time for the population is ________ year(s).

Question

Quizplus · Accepted Answer

To find the doubling time, we can use the rule of 70. The rule of 70 states that to find the doubling time, we divide the number 70 by the annual growth rate (as a percentage).

First, we need to find the annual growth rate.

Starting population = 100 
Ending population = 1600 
Time = 8 years

Annual growth rate = ((ending/start)^(1/time))-1 
Annual growth rate = ((1600/100)^(1/8))-1 = 2.363

Now we can use the rule of 70:

Doubling time = 70/growth rate 
Doubling time = 70/2.363 = 29.6 or approximately 30

So the doubling time for this population is 30 years. Choice D is the best answer.

A Population Is Counted at 100 Individuals in 1998