Tax Rates. Based on the amounts of taxable income below, compute the federal income

tax payable in 2015 on each amount assuming the taxpayers are married filing a joint

return. Also, for each amount of taxable income, compute the average tax rate and the

marginal tax rate.

Taxable income of $30,000.

. Taxable income of $100,000.

. Taxable income of $375,000.

. Taxable income of $600,000.