A population doubles every 30 years. Assuming exponential growth find the following:

Question

annual growth rate: %
continuous growth rate: %

Answer 1

2 = 1(1+i)^20
take 20th root of both sides
1.03526 = 1+i
i = .03526

the rate is 3.526%

continuous growth:
2 = e^(20k)
ln 2 = 20k(lne)
k = ln2/20 = .03466 or 3.466%