Suppose $60,000 is invested into an account where interest is compounded annually. After 30 years the balance is $224,719. What was the interest rate as a percent?

Answer 1

224,719 = 60,000(1 + r/1)¹⁽³⁰⁾

224,719/60,000 = (1 + r)³⁰

(224,719/60,000)^1/30 = 1 + r

r = (224,719/60,000)1/30 - 1

r = 0.0449

4.5%