The following linear programming model formulation is used tor the production of tour difterent products, with two different manulacturing processes and two different material requirements: maximizeZ=50x1+58x2+46x3+62x4subjectto4x1+3.5x2+4.6x3+3.9x4600hr.(process1)2.1x1+2.6x2+3.5x3+1.9x4500hr.(process2)15x1+23x2+18x3+25x43,600Ib.(materialA)8x1+12.6x2+9.7x3+10.5x41,700Ib.(materialB)x1+x2+x3+x1x1+x2.60x1,x2,x3,x40 a. Solve this problem by using the computer. b. Identify the sensitivity ranges for the objective function coefficients and the constraint quantity values. c. Which is the most valuable resource to the firm? d. One of the four products is not produced in the optimal solution. How mwch would the profit for this product have to be for it to be produced