Corporate taxes: Tantor$$ Supply, Inc., is a small corporation acting as the exclusive distributor of a major line of sporting goods. During $2021$ the firm earned $$1,740,100$ before taxes.

a$.$ Calculate the$$ firm's tax liability using a flat tax rate of $21\%.$

b$.$ How much are Tantor$$ Supply's $2021$after$-$tax earnings?

c$.$ What was the$$ firm's average tax$$ rate?

d$.$ What was the$$ firm's marginal tax$$ rate?