Scot and Vidia, married taxpayers, earn $95,000 in taxable income and $5,000 in interest from an investment in City of Tampa bonds. (Use the U.S. tax rate schedule). (Do not round intermediate calculations. Round your answer to 2 decimal places.)

a.	If Scot and Vidia earn an additional $83,500 of taxable income, what is their marginal tax rate on this income?

b.	How would your answer differ if they, instead, had $83,500 of additional deductions?