PLEASE SHOW ALL WORKING:Your company has raised financing by issuing $20-$year bonds on January $1,2010.$ They

mature on December $31,2030$ and have a par value of $$1,000$ and a coupon rate of $9\%.$

Coupon payments are made semi$-$annually.

a$.$ What would the value of the bonds be on June $30,2017,$ if interest rates had risen

to $10\%?$

b$.$ What would be their value on December $31,2023,$ if interest rates had fallen to

$7\%?$

c$.$ If the bonds had a value of $$975\mathrm{.}00$ on December $31,2025,$ what would be their

yield to maturity on that date?