the population of a city was 35,000 in 1996, and it grows at an annual rate of 8%?

Question

the population of a city was 35,000 in 1996, and it grows at an annual rate of 8%?
a)how long will it take for the population to double at this rate?
b) if the growth arte changes in 2007, what will the estimated population be in 2015

for part b the growth rate changes to 6.5%

Answer 1

a) (1.08)^n = 2, so n ln(1.08) = ln(2), and n = ln(2)/ln(1.08) = 9, so 9 years.

b) (1.08^10)*(1.065^9)*35000 = 133,184

Answer 2

a) Multiply the population by .08 then add the product to the population

9 years, 11 months, 3 weeks

b) multiply the population by 6.5% (or .065) then add the product to the population.

116, 500

Answer 3

a.)
35000*(1+.08*x)=65000, now solve for x and you got answer

b) not enough information, because we dont know what the rate changes to

Answer 4

a) About 9.5 years
b) Unable to answer without new growth rate