$1\mathrm{.}10$ Use an IF function with nested VLOOKUP functions to calculate the Federal Income Tax Rate.

a$.$ The federal tax rate is a function of the adjusted income and the employee's marital status.

b$.$ Reference the tax tables in the Model Assumptions and the marital status in the Employee Information section to construct a formula $($set of nested formulas$)$ to calculate the tax rate.

c$.$ For example, a single employee who earned $$15,000$ would pay a $33\%$ marginal tax rate.