# Compound Interest

• March 23rd 2009, 05:03 PM
tmac11522
Compound Interest
A sum of $1000 was invested for 4 years, and the interest was compounded semiannually. If this sum amounted to$1441.26 in the given time, what was the interest rate?
• March 23rd 2009, 05:25 PM
skeeter
Quote:

Originally Posted by tmac11522
A sum of $1000 was invested for 4 years, and the interest was compounded semiannually. If this sum amounted to$1441.26 in the given time, what was the interest rate?

$A = A_0\left(1 + \frac{r}{n}\right)^{nt}$

$1441.26 = 1000\left(1 + \frac{r}{2}\right)^8$

solve for $r$