Dana intends to invest $30,000 in either a Treasury bond or a corporate bond. The Treasury bond yields 5 percent before tax and the corporate bond yields 6 percent before tax. Required: a-1. Assuming Dana's federal marginal rate is 24 percent and her marginal state rate is 5 percent, which of the two options should she choose? Assume that Dana itemizes deductions. a-2. How much interest after-tax would Dana earn by investing in the corporate bond? Note: Do not round intermediate calculations and round your final answer to the nearest whole dollar amount. b-1. If she were to move to another state where her marginal state rate would be 10 percent, which of the two options should she choose? Assume that Dana itemizes deductions. b-2. How much interest after-tax would Dana earn by investing in the corporate bond as per requirement b-1? Note: Do not round intermediate calculations and round your final answer to the nearest whole dollar amount.