A flat income tax sets the same tax rate for all levels of income, say 10%.A progressive income tax sets progressively higher tax rates for higher levels of income, at the margin; for example, the rate might be 5% on the first $10,000 you earn, and 15% for all earnings above $10,000.Considering the marginal utility of income, provide an argument for why a progressive tax system might be preferable to a flat tax system in terms of its effects on total utility.