10. Problem 2-12 (Corporate After-Tax Yield) decimal places. After-tax rate of return on AT\&T bond: After-tax rate of return on AT\&T preferred stock: % After-tax rate of return on Florida muni bonds: % 10. Problem 2-12 (Corporate After-Tax Yield) decimal places. After-tax rate of return on AT\&T bond: After-tax rate of return on AT\&T preferred stock: % After-tax rate of return on Florida muni bonds: %