Susan and Stan Britton are a married couple who file a joint income tax retum, where the tax rates are based on the tax table 3.5. Assume that their taxable income this year was $151,000. 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. % mrackets appeoacnes 3/ as taxabve income nses wotnout umit. 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%