i got 9 years

A four-year $1,000 bond will pay $70 in interest at the end of each year. With a yield-to-maturity of 8%, its present market price is $934. Its duration is A. Show the Formula of duration (0.1 point) B. Create the Table (0.6 point) C. Show the steps to get the market price (0.2 point) D. Show the steps to get the duration (0.2 point)