Mr. Madoff invests 1000 dollars in a fund that compounds annually at a constant interest rate. After three years, his investment has grown to 1861 dollars. What is the annual interest rate? (Round your answer to the nearest integer.)
1861 = 1000 (1+x)3
1861/1000 = (1+x)3 take cube root of both sides
1.23 = 1+x
x = .23 = 23 %