Required: a. What are the tax liability, the marginal tax rate, and the average tax rate for a married couple filing jointly with $51,900 taxable Income? b. What are the tax liability, the marginal tax rate, and the average tax rate for a single individual with $197,200 taxable income? c. What are the tax liability, the marginal tax rate, and the average tax rate for a head of household with $446,300 taxable income?