Find the required annual interest rate to the nearest tenth of a percent for $1200 to grow to $1600 if interest is compounded quarterly for 10 yr.

Question

A=P(1+r/n)^tn

I know how to plug it in, but when I work it out I always get the wrong answer.

Answer 1

$1600 = $1200(1 + r/4)^40

1600/1200 = 4/3 = (1 + r/4)^40

1 + r/4 = 1.007218

r/4 = .007218

r = .02887

about 2.9%