A portfolio contains 50% of Bond I, 20% of Bond II, 20% of Bond III and 10% of Bond IV. Details of the four bonds are given below: I. II. 10-year zero coupon government bond, par value $1000, current price = $613.91 10-year zero coupon corporate bond, par value $1000, default premium= 2.5% 5 year 15% coupon corporate bond, par value $1000, annual coupon payments, default premium = 9% and YTM for similar government bond is 6% III. IV. 5 year 15% government coupon bond, par value $1000, annual coupon payments, YTM=6% a. Find the prices of Bond II, Bond III, and Bond IV. (2 marks) b. What are the Macaulay's durations of Bond III and Bond IV? (4 marks)