There are 225 wolves in a state park. The population is increasing at the rate of 15% per year. When will the population reach 500?

1 Answer
Apr 16, 2016

Between years 5 and 6.

Explanation:

Population after nn years is given by the formula
color(white)("XXX")P_n=225xx(1.15)^nXXXPn=225×(1.15)n

We are asked when
color(white)("XXX")Pn = 500XXXPn=500

color(white)("XXX")225xx(1.15)^n = 500XXX225×(1.15)n=500

color(white)("XXX")rarr 1.15^n = 500/225=20/9XXX1.15n=500225=209

color(white)("XXX")log_(1.15) (20/9) = nXXXlog1.15(209)=n

Using a calculator
color(white)("XXX")log_1.15 (20/9) ~~5.7133XXXlog1.15(209)5.7133