Mango Inc. is going to issue a $25-$year bond with a coupon rate of $3\mathrm{.}00\%($with $3$

coupon payments per year$)$ and a face value of $$1,000.$ Mango Inc. believes it can be

rated A by Standard and Poor's. However, because of recent financial difficulties at

the company, Standard and Poor's is warning that it may downgrade Mango Inc.

Industries bonds to BBB$.$ Yields on A$-$rated, long$-$term bonds are currently $5\mathrm{.}00\%$

$($quoted as an annual percentage rate $($APR$)),$ and yields on BBB$-$rated bonds are

$9\mathrm{.}30\%($quoted as APR$).$ What is the $\%$ change in the price of the bond if it is

downgraded?