For tax year 2021

Charles is a single taxpayer has the following income and deductions for the current tax year: INCOME Salary 70,000 Business Income 25,000 Interest Income from bonds 10,000 Tax-exempt bond interest 5,000 Total Income 110,000 DEDUCTIONS Business expenses 10,000 Itemized deductions 20,000 Personal exemptions 4,050

Compute the taxable income and federal tax liability for the current year.

Compute the marginal, average and effective tax rates.

For tax planning purposes, which of the three rates in part 2 is the most important?