Calculate the after-tax return of a 11.79 percent, 20-year, A-rated corporate bond for an investor in the 15 percent marginal tax bracket. Compare this yield to a 8.42 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 33 percent marginal tax bracket. The after-tax return of a 11.79 percent, 20-year, A-rated corporate bond for an investor in the 15 percent marginal tax bracket is (Round to two decimal places.)