Answer:
 $7724
Step-by-step explanation:
Her estimated quarterly income is $73,040/4 = $18,260.
Her estimated tax rate is ...
 27% + 12.4% + 2.9% = 42.3%
This tax rate applied to her estimated earnings gives an estimated quarterly tax of ...
 $18,260 × 0.423 = $7723.98
 ≈ $7724 . . . . . taxes are rounded to the nearest dollar