Marginal corporate tax rates Using the corporate tax rate schedule given in the previous problem, perform the following:

a. Find the marginal tax rate for the following levels of corporate earnings before taxes: $12,000; $40,000; $70,000; $90,000; $300,000; $550,000; $1.3 million;

and $22 million.

b. Plot the marginal tax rate (measured on the y-axis) against the pretax income levels

(measured on the x-axis). Explain the relationship between the marginal tax rate and pretax income levels.