8. A bond's rating provides a guide to its price. As we write this in 2009, Aaa bonds yield \( 5.45\% \) and Baa bonds yield \( 8.67\% \). If some bad news causes a \( 10\% \) five year bond to be unexpectedly downrated from Aaa to Baa, what would be the effect on the bond price? (Assure annual coupons with face value $1,000) (10分)