
Carol H. answered 09/28/14
Tutor
4.9
(285)
Experienced Mathematics Tutor w/ Master's Degree in Math
The formula for interest compounded at various intervals is:
A = P(1 + r)nt
n
A = final amount, P = principal, r = interest rate, n = number of intervals, and t = time (in years)
40,000 = P(1 + .08)4(2)
4
40,000 = P(1 + .02)8
40,000 = P(1.02)8
40,000 = P(1.171659381) divide both sides by that huge decimal
$34,140 = P