1. Alan is a single taxpayer with a gross income of $88,000, a taxable income of $66,000, and an income tax liability of $10,460 for 2018. Alan also has $8,000 of tax-exempt interest income. What are Alan's marginal, average, and effective tax rates?
   1. 22% marginal; 14.5% average; 15.8% effective.
   2. 24% marginal; 14.5% average; 15.8% effective.
   3. 12% marginal; 15.8% average; 14.1% effective.
   4. 22% marginal; 15.8% average; 14.1% effective.