Marginal tax rates Using the tax rate schedule given here $($i$),$ perform the following:

a$.$ Find the marginal tax rate for the following levels of sole proprietorship earnings before taxes: $$16,700$;$$59,100$; $$91,000$;$$154,000$;$$256,000$;$$457,400$; and $$1$ million.

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

a$.$ The marginal tax rate for earnings before taxes of $$16,700$ is

$\%.($Round to the nearest integer.$)$