What is the duration of a bond purchased for $948.50 which matures in 5 years and has a coupon rate of 12.5% with annual coupon payments? What is the duration of a bond purchased for $926.97 that matures in 7 years with an annual coupon rate of 8.5%? If the 2 above bonds were placed into a portfolio with a third bond that was purchased for $1,018.02 that matures in 5 years with an annual coupon rate of 12.5%, what would the duration of the portfolio be if each holding was equally weighted?