A recent college graduate decides to invest the $ 8,000 he received for his college graduation in a fund earning 12% annual interest for four years. At the end of the four- year period, he expects to withdraw the money to purchase a reasonably priced used car. Answer the following questions:
a. What amount would the graduate withdraw after four years, if the investment earns simple interest?
b. What amount would the graduate withdraw after four years if interest is compounded annually?
c. What amount would the graduate withdraw after four years if interest is compounded semiannually?
d. What amount would the graduate withdraw after four years if interest is compounded quarterly?