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: $8,700; $78,300; $301,000; $500,000; $1,600,000; $9.7 million; and $20.3 million. 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.