Chuck, a single taxpayer, earns $$77,200$ in taxable income and $$12,400$ in interest from an investment in City of Heflin bonds. $($Use the U$.$S$.$ tax rate schedule.$)$

Required:

a$.$ If Chuck earns an additional $$40,000$ of taxable income, what is his marginal tax rate on this income?

b$.$ What is his marginal rate if$,$ instead, he had $$40,000$ of additional deductions?

Note: For all requirements, do not round intermediate calculations. Round percentage answers to $2$ decimal places.

$\backslash$table$[[$a$.$ Marginal tax rate,$53\mathrm{.}58,\%$