Required:

a$.$ Find the duration of a $7\%$ coupon bond making annual coupon payments if it has three years until maturity and a yield to maturity of

$7\mathrm{.}1\%.($Do not round intermediate calculations. Round your answers to $4$ decimal places.$)$

b$.$ What is the duration if the yield to maturity is $11\mathrm{.}1\%?($Do not round intermediate calculations. Round your answers to $4$ decimal

places.$)$