Campbell, a single taxpayer, earns $$406,000$ in taxable income and $$2,480$ in interest from an investment in State of New York bonds. $($Use the U$.$S$.$ tax rate schedule.$)$ Required: a $.$ If Campbell earns an additional $ $16,200$ of taxable income $,$ what is her marginal fa rate on this income $?$ b $.$ What is her marginal rate if$,$ instead $,$ she had $$16,200$ of additional deductions $?$ Note: For all requirements $,$ do not round intermediate calculations $.$ Round percentage answers to whole percent.