The population of a southern city follows the exponential law. If the population doubled in size over 23 months and the current population is 80,000​, what will the population be 3 years from​ now?

Answer 1

Time to double = 70/r

Where r = growth rate (in percentage)

23 = 70/r

r = 70/23 [in percentage]

80000*(1+70/23*1/100)^3 = 87528.909

The population will be approximately 87,529 in 3 years.

Answer 2

t = number of months elapsed from the moment the population was p₀

p₀ = initial population = 80,000

doubling period = 23 months

p(t) = p₀ (2)^t/23,

with t in months.

3 years = 36 months

p(36) = 80,000 (2)^36/23 = ?