Modified duration

Dear Sir

I was watching your revision lecture whereby you did the modified duration of the annuity lease payment of 60 million

I notice you added them all up and divided by the opening figure of 60 the divided by the 1.02 interest rate to get the modified duration. i will assume ( and I am asking) that if it is a normal project with different numbers like Mock 3 Q2 BPP whereby they want project duration and you do the percentages taht if they wanted modified duration thyen you would take the 2.47 and divide by the 11% cost of capital??