Susan and Stan Britton are a married couple who file a joint income tax return, where the tax rates are based on the tax table 3.5. Assume that their taxable income this year was $301,000. Do not round intermediate calculation. a. What is their federal tax liability? Round your answer to the nearest dollar. $ b. What is their marginal tax rate? Round your answer to the nearest whole number. % c. What is their average tax rate? Round your answer to two decimal places. % 2020 Individual Tax Rates 2. The average tax rates are always below the marginal rates, but in 2020 the average at the top of the brackets approaches 37% as taxable income rises without limit. 3. In 2018, the personal exemption for the taxpayer and dependents was eliminated. With the deduction limitation on state and local property, income, and sales taxes and the existence of payroll taxes (Social Security and Medicare taxes), the 2020 effective tax rate will be higher than 37%