A boy invests a sum of $4000 on his 10th birthday in the year 1996, with an annual interest rate of 7%, compounded every six months. During some stage of the investment, the interest rate changes to an annual rate of 6%, still compounded every six months. On the boy's 18th birthday, the boy checks his account to see a sum of $6770. At what point in time did the interest rate change from 7% to 6%?

Excel spread sheet gave me a drop in interest rates on the boy's birthday in 2002. He was 16 at the time, wondering why he didn't invest in Google when he was 12.

Posted by Leming on 2006-10-04 10:35:13