Isabel, a calendar year taxpayer uses the cash method of accounting for her sole proprietorship. In late December she received a $24000 bill from her accountant for consulting services related to her small business Isabel can pay the $24,000 bill anytime before January 30 of next year without penalty. Assume her marginal tax rates 37 percent this year and next year, and that she can earn an after-tax rate of return of 7 percent on her investments . What is the after-tax cost i Isabel pays the $24,000 bill in December? Aux cool b. What is the after-tax cost of het pays the $24.000 bill in January? Use fisht:39. (Round your answer to the nearest whole dollar amount.) Art.com