Thread: effective interest rate

Here's one that is giving me brain freeze. Thank you in advance for any help>

At what effective interest rate will a sum of money be tripled in eight years when the interest is compounded quarterly?

Solve for i

(1+i)^(4*8) = 3

Calculate j

(1+i)^4 - 1 = j

Alternatively, one could solve directly for j with only a little thought.

now i see. thank you very much