alculate the$$ after$-$tax return of$$ a$($n$)4\mathrm{.}75$percent$,20-$year,$$ A$-$rated corporate bond for an investor in the $10$ percent marginal tax bracket. Compare this yield to$$ a$($n$)4\mathrm{.}22$percent$,20-$year,$$ A$-$rated, tax$-$exempt municipal$$ bond, and explain which alternative is better. Repeat the calculations and comparison for an investor in the $35$ percent marginal tax bracket.