Problem $7-21$ Bond Yields $[$LO$2]$

Williams Software has $10\mathrm{.}8$ percent coupon bonds on the market with $18$ years to maturity. The bonds make semiannual payments and currently sell for $108\mathrm{.}2$ percent of par.

a$.$

What is the current yield on the bonds? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ What is the YTM$?($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

c$.$ What is the effective annual yield? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$