Ms$.$ Busch has gathered these data about her finances: Salary $140,000$ Taxable interest received $2,500$ Municipal bond interest received $15,000$ Total itemized deductions $8,000$ The personal exemption is $$3,700.$ The standard deduction for a single filer is $$5,800.$ Use the rate schedule in Figure $92$ to compute the following: a$.$ Her tax b$.$ Her average effective tax rate c$.$ Her average tax rate d$.$ Her marginal tax rate e$.$ Her accountant discovers a previously omitted personal deduction of $$800.$ By how much does her federal tax liability fall with that addition? f$.$ Amazingly enough, the accountant now discovers a $$250$ credit omitted from previous calculations $($but after discovering the $$800$ in part e$).$ By how much does her federal tax liability fall because of this credit?