Question 996410
f = p * (1+r)^n


if you divide both sides of this equation by p, you will get:


f/p = (1+r)^n


f = future value
p = present value
r = annual interest rate
n = number of years


in your problem:


f = 343
p = 216
n = 3


f/p = (1+r)^n becomes 343/216 = (1+r)^3


take the cube root of both sides of this equation to get:


(343/216)^(1/3) = 1+r


subtract 1 from both sides of this equation to get:


(343/216)^(1/3) - 1 = r


solve for r to get:


r = .1666666667


343/216 = (1+r)^n becomes:


343/216 = (1.1666666667)^3


simplify to get:


1.587962965 = 1.587962963


this confirms the solution is correct.


annual interest rate is 16 and 2/3 %.