Calculate the after-tax return of a 13.73 percent, 20-year, A-rated corporate bond for an investor in the 15 percent marginal tax bracket. Compare this yield to a 10.02 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.

The after-tax return of a 13.73 percent, 20-year, A-rated corporate bond for an investor in the 15 percent marginal tax bracket is ___%?