It's hard to say what you did wrong when you don't show what you did! I suspect that you used the formula, P(1+ r)^n, where n is the number of compounding periods and r is the interestper compounding period, incorrectly. It looks like you used n= 4, which is correct, compounding every have year for two years means compounding 4 times, but used r= .03 which is wrong. An interest rate of 3% means 3/2= 1.5% or .015 semi-annually.