Hello, I need some help figuring out how to calculate the marginal tax rates for this problem. All I ask is for work to be shown so that I may follow along and figure out how to calculate everything. Thank you! The problems and tax rate schedules will be attached below.

Chuck, a single taxpayer, earns $76,800 in taxable income and $11,900 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. 2023 Tax Rate Schedules Individuals Cobndwlo V Cimmla