Exercise F4 Write a void function without parameters computeTaxNet that uses the gross pay of an individual to compute his tax deduction and net pay that are printed in function main. The tax deduction is computed as follows: if the gross pay is greater than or equal to $1000.00, then the tax deduction is 25% of the gross pay; otherwise, it is 18% of the gross pay. The net pay is the gross pay minus the tax deduction. a. Function main first calls function computeTaxNet to compute the tax deduction and the net pay for the gross pay $1250. b. It then reads the gross pay of an individual and then calls function computeTaxNet to compute his tax deduction and net pay. c. You must first determine and define the global variables of this program; then write function computeTaxNet, and finally write function main