Compute the Macaulay duration under the following conditions:

a. A bond with a four-year term to maturity, a 10 percent coupon (annual payments), and a market yield of 8 percent.

b. A bond with a four-year term to maturity, a 10 percent coupon (annual payments), and a market yield of 12 percent.

c. Compare your answers to Parts a and b. Assuming it was an immediate shift in yields, discuss the implications of this for classical immunization