I need help on D please

Kalyan Singhal Corp. makes three products, and it has three machines available as resources as given in the following LP problem: Maximize contribution = 4X, +4X2 +7X3 1X1 + 7X2 + 4X3 = 100 2X1 + 1X2 + 7X3 = 110 8X, +4X2 +1X3 = 100 X4, X2, X3 20 (C1: hours on machine 1) (Cz: hours on machine 2) (C3: hours on machine 3) a) Using a computer software for solving LP, the optimal solution achieved is: X4 = 7.95 (round your response to two decimal places). X2 = 5.95 (round your response to two decimal places). X3 = = 12.59 (round your response to two decimal places). Contribution (objective value) = 143.76 (round your response to two decimal places). b) Machine 1 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). Machine 2 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). Machine 3 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). c) An additional hour of time available for third machine, is worth 0.26 dollars to the firm (round your response to two decimal places). d) An additional 8 hours of time available for the second machine, at no cost to the firm, are going to increase the objective value by dollars (round your response to two decimal places)