Jill and George are married and file a joint return. They expect to have $ 420,000 of taxable income in the next year and are considering whether to purchase a personal residence that would provide additional tax deductions of $ 42,000 for mortgage interest and real estate taxes. a. What is their marginal tax rate for purposes of making this decision? (Enter amounts as percentages to one decimal place.) What is the marginal tax rate if the personal residence is not purchased? % What is the marginal tax rate if the personal residence is purchased?