A pension fund manager is holding a $8-$year $5\mathrm{.}8\%$ coupon bond in the fund$$s portfolio, and the interest rate is currently $7\mathrm{.}5\%.$ The par$-$value of the bond is $$1,000.$ Unfortunately for you, the interest rate rose which caused the price of the bond to fall by $5\%.$ What did th interest rate rise to$?($hint: you need to know the duration of the bond$)$