Joseph is a single taxpayer with a gross income of $88,000, a taxable income of $66,000, and an income tax liability of $10,310 for 2020. Joseph also has $8,000 of tax-exempt interest income. What are Joseph's marginal, average, and effective tax rates? 22% marginal; 15.6% average; 13.9% effective. O 12% marginal; 15.6% average; 13.9% effective. 24% marginal; 13.9% average; 15.6% effective. O a) 22% marginal; 13.9% average; 15.6% effective. Donna is a student at Eastern State University. She receives a $4,000 academic scholarship from the Silverman Foundation. She also has a $2,000 assistantship to grade and tutor for the Department of Economics. Tuition, books, fees, and supplies are $5,000. How much gross income must Donna recognize from the scholarship and assistantship? 0 $1,000 0 $6,000 0 $2,000 0 $-0- O $5,000