9. An insurance company is analyzing the following three bonds, each with 6 years to maturity, annual interest payments, and is using duration as its measure of interest rate risk: ( L6 ) a. $10,000 par value, coupon rate =8%,rb=0.10 b. $10,000 par value, coupon rate =10%,rb=0.10 c. $10,000 par value, coupon rate =12%,rb=0.10 What is the duration of each of the three bonds