How to find the interest between present and future value?

Question

Present Value

$400

Years

11

Future Value

$684

Answer 1

FV = PV * (1 + i)^n

684 = 400 * (1 + i)^11

684/400 = (1+i)^11

log(684/400) = log( (1+i) ^ 11)

log(684/400) = 11 * log (1 + i)

log(684/400) / 11 = log (1+ i)

10^((log(684/400))/11) = 10 ^ log (1+i)

10^((log(684/400))/11) = 1 + i

i = 10^((log(684/400))/11) - 1

i = 10^0.021181465 - 1

i = 1.04998 - 1

i = 0.04998

4.998 % / year