Using the individual tax rate schedule perform the following:

a$.$ Calculate the tax liability, after$-$tax earnings, and average tax rates for the following levels of partnership earnings before taxes: $$14,700$;$$75,500$;$$323,000$;$$495,000$;$$1\mathrm{.}3$ million; $$1\mathrm{.}5$ million; and $$2\mathrm{.}1$ million.

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