Scott and Laura are married and will file a joint tax return. Scott has a sole proprietorship (not a "specified services" business) that generates qualified business income of $300,000. The proprietorship pays W-2 wages of $40,000 and holds property with an unadjusted basis of $10,000. Laura is employed by a local school district. Their taxable income before the QBI deduction is $386,600 (this is also their modified taxable income).

a. Determine Scott and Laura's QBI deduction, taxable income, and tax liability for 2020.

b. After providing you with the original information in the problem, Scott finds out that he will be receiving a $6,000 bonus in December 2020 (increasing their taxable income before the QBI deduction by this amount). Redetermine Scott and Laura's QBI deduction, taxable income, and tax liability for 2020.

c. What is the marginal tax rate on Scott's bonus?