Roman C. answered 10/30/12
Masters of Education Graduate with Mathematics Expertise
The formula for annual compound interest is A=P(1+r/n)nt where:
A = final amount
P = principal amount (initial investment)
r = annual nominal interest rate (as a decimal, not in percentage)
n = number of times the interest is compounded per year
t = number of years
In your problem we have P=3400, r=0.12, n=2, t=5, so we just need to plug these values in:
A = 3400*(1+0.12/2)2*5 = 3400*1.0610 = 6088.882168245702313984 which rounds to 6088.88 for the final balance.
The total interest is 6088.88-3400 = 2688.88