Computing CD Interest. A certificate of deposit will often result in a penalty for withdrawing funds before the maturity date. If the penalty involves two months of interest, what would be the amount for early withdrawal on a $20,000, 4 percent CD? Computing Future Value. What would be the value of a savings account started with $1,200, earning 3 percent (compounded annually) after 10 years? Computing Future Value. What would be the value of a savings account started with $1,200, earning 3 percent (compounded annually) after 10 years