3.6 For a single taxpayer with taxable income of $70,000, total taxes paid are .10 8,025+ [.15 (32,550 -8,025)] + [.25 x (70,000-32,550)] = $13,843.75 The marginal tax rate is 25%, but the average tax rate is only 13,843.75/70,000 = .1987, or 19.87%. For the married taxpayers filing jointly with taxable income of $70,000, total taxes paid are (.10 x 16,050)+.15(65,100 16,050)+.25(70,000-65,100) $10,187.50 The marginal tax rate is 25%, and the average tax rate is 10,187.50/70,000 = .146, or 14.6%.