42. Havel and Petra are married and will file a joint tax return. Havel has W-2 income of $38,588, and Petra has W-2 income of $46,227. What is their tax liability? Determine their tax liability using both the tax tables and the tax rate schedule. 43. Determine the tax liability, marginal tax rate, and average tax rate (rounded to two decimal places) in each of the following cases. Use the tax tables to determine tax liability. a. Single taxpayer, taxable income of $31,916 : Liability = Marginal = Average = b. Single taxpayer, taxable income of $97,463 : Liability = Marginal = Average =