a. Find the marginal tax rate for the following levels of corporate earnings before taxes: $11,000, $81,600, $304,000, $496,000, $1,300,000, $9/3 million, and $20.4 million

b. B. Plot the average tax rates (measured on the y axis) against the pretax income levels (measured on the x asis). What generalization can be made concerning the relationship between these variables.

To find the marginal tax rate for different levels of corporate earnings before taxes, you will need to refer to the tax rate schedule provided by the tax authority in your country. Generally, tax rates are progressive, meaning that they increase as the earnings increase.

a. Here's how you can find the marginal tax rate for each level of earnings:

1. Look up the tax rate schedule for corporate earnings before taxes in your country. This schedule will provide you with the applicable tax rates at different income brackets.

2. Identify the income bracket that each earnings level falls into. For example, if the tax rate changes at $10,000, $80,000, $300,000, $500,000, $1,000,000, $3,000,000, and $20,000,000, you would categorize the earnings accordingly.

3. Determine the applicable tax rate for each income bracket. For example, if the tax rate for earnings between $0 and $10,000 is 10%, and the tax rate for earnings between $10,001 and $80,000 is 15%, you would assign the corresponding tax rate for each earnings level.

b. To plot the average tax rates against the pretax income levels, follow these steps:

1. Calculate the average tax rate for each income level using the formula: Average Tax Rate = Tax Paid / Pretax Income.

2. Create a graph with the pretax income levels on the x-axis (in ascending order) and the average tax rates on the y-axis.

3. Plot the data points for each income level and connect them with a line.

The generalization you can make regarding the relationship between these variables would depend on the specific tax rate schedule in your country. Generally, as pretax income levels increase, the average tax rate tends to increase, indicating a progressive tax system. However, the specific pattern may vary based on the tax rates applicable at different income brackets.