What would be the marginal and average tax rates for a married couple with taxable income of $89,600? For an unmarried taxpayer with the same income? Use Table 3.7. (Do not round intermediate calculations. Enter the marginal tax rate as a percent rounded to 1 decimal place. Enter the average tax rate as a percent rounded to 1 decimal place.) a. What would be the marginal tax rate for a married couple with income of $89,600? Marginal tax rate for a married couple % b. What would be the average tax rate for a married couple with income of $89,600? Average tax rate for a married couple % 4 c. What would be the marginal tax rate for an unmarried taxpayer with income of $89,600? Marginal tax rate for an unmarried taxpayer % d. What would be the average tax rate for an unmarried taxpayer with income of $89,600? Average tax rate for an unmarried taxpayer %