You have the right equation.
p(x) = 0.586041x - 3,200,000
3200000 of course represents the deduction from the loan
0.586041 - this number represents the amount of money left after taxes (58.6041% of the total is left)
We get this by taking into account all the taxes on top of another...
35% federal tax = 65% left
35% federal tax and 8% state tax = 65% x 92% left
35% federal tax and 8% state tax and 2% local tax = 65% x 92% x 98% left = 58.6041%
To get the profit plug in the given taxable income for x.
p(6775989) = 0.586041(6775989) - 3,200,000 = $771,007.37 approx.
answer: $771,007.37 approx.
