Alan and Sara Winthrop are a married couple who file a joint income tax return. They have two children, so they claim a total of 4 exemptions ($4,050 for each exemption). In addition, they have legitimate itemized deductions totaling $25,750. Their total income from wages is $213,900. Assume the following tax table is applicable: Married Couples Filing Joint Returns If Your Taxable Income Is Up to $18,650 You Pay This Amount on the Base of the Bracket Plus This Percentage on the Excess over the Base Average Tax Rate at Top of Bracket $0.00 10.0% 10.0% $18,650-$75,900 1,865.00 15.0 13.8 $75,900-$153,100 10,452.50 25.0 19.4 $153,100-$233,350 29,752.50 28.0 22.4 $233,350-$416,700 52,222.50 33.0 27.1 $416,700-$470,700 112,728.00 35.0 28.0 Over $470,700 131,628.00 39.6 39.6 What is their marginal tax rate?