Suppose that in 2011, Congress passed and the president signed a new simple income tax with a flat rate of 25 percent on all income over $25,000 (no tax on the first $25,000). Assume that the tax is imposed on every individual separately. For each of the following total income levels, calculate taxes due and compute the average tax rate. Plot the average tax rate on a graph with income along the horizontal axis. Is the tax proportional, progressive, or regressive? Explain why.

a. $25,000

b. $35,000

c. $45,000

d. $60,000

e. $80,000

f. $100,000