2- Your aunt is planning to invest in a bank CD that will pay 7.5 percent interest semiannually. If she has $5,000 to invest, how much will she have at the end of four years? 3- Your brother has asked you for a loan and has promised to pay back $7,750 at the end of three years. If you normally invest to earn 6 percent per year, how much will you be willing to lend to your brother?