3) How much money should be invested at 8% per year so that after 2 years the amount will be $10,000 when the interest is compounded monthly? 4) To save for his son's college education, Mr. Graff decides to put $50 aside every month in a credit union account paying 10% interest compounded monthly. If he begins this saving program when his son is 3 years old, how much will he have saved by the time his son is 18 years old