PERSONAL TAXES 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 $186,000. Round your answers to two decimal places. a. What is their federal tax liability? $ b. What is their marginal tax rate? % c. What is their average tax rate? % Table 3.5 2015 Individual Tax Rates Single Individuals If Your Taxable Income Is Up to $9,225 $9.225-537,450 $37,450 $90,750 $90,750-$189,750 $189,750-$411,500 $411,500-$$413,200 Over $413,200 You Pay This Amount on the Base of the Bracket $ 0 922.50 5.156.25 18.48 1.25 46,075.25 119,401.25 119,996.25 Plus This Percentage on the Excess over the Base (Marginal Rate) 10.0% 15.0 25.0 28.0 33.0 35.0 39.6 Average Tax Rate at Top of Bracket 10.0% 13.8 20.4 24.3 29.0 29.0 39.6 Married Couples Filing Joint Returns If Your Taxable Income Is Up to $18.450 $18.450-$74,900 $74.900-5151,200 S151,200-$230,450 $230,450-$411,500 $411,500-$464,850 Over $464,850 You Pay This Amount on the Base of the Bracket S 0 1,845.00 10,312.50 29,387.50 51,577.50 111,324.00 129,996.50 Plus This Percentage on the Excess over the Base (Marginal Rate) 10.0% 15.0 25.0 28.0 33.0 35.0 39.6 Average Tax Rate at Top of Bracket 10.0% 13.8 19.4 22.4 27.1 28.0 39.6