Marginal corporate tax rates Using the corporate tax rate schedule given in Table 1.4, perform the following: a. Find the marginal tax rate for the following levels of corporate earnings before taxes: $ 15,000; $ 60,000; $ 90,000; $ 200,000; $ 400,000; $ 1 million; and $ 20 million. Answer: 40% x 21765,000=830600,000 net profit before tax. b. Plot the marginal tax rates (measured on the y axis) against the pretax income levels (measured on the x axis). Explain the relationship between these variables