You can invest in taxable bonds that are paying a yield of 9.1 percent or a municipal bond paying a yield of 7.35 percent. Assume your marginal tax rate is 21 percent. a. Calculate the after-tax rate of return on the taxable bond? (Round your answer to 2 decimal places. (e.g., 32.16)) b. Which security bond should you buy? a b. Rate of return The security bond one should buy is