http://educ.jmu.edu/~drakepp/investments/problems/duration.pdf ^ I need help with Bond C. For bond C, the maturity is 10 yrs, the coupon 4.5%, the yield 6.5%, and the par value $1000. In this problem I'm supposed to calculate the modified and effective durations of the bond. So I also need to calculate the Macaulay duration. I've tried the last two bonds and got the right answer. But for bond C, I'm not getting the right Macaulay duration (the solution is included in the pdf btw). I keep getting 7.979 yrs. Could someone explain step by step please? Thanks