Timmy Tappan is single and had $183,000 in taxable income. Using the rates from Table 2.3 in the chapter, calculate his income taxes. a. What is the average tax rate? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) b. What is the marginal tax rate? (Do not round intermediate calculations and enter your answer as a percent rounded to the nearest whole number, e.g., 32.)