Consider the following lp: maximize z = 2x1 + 4x2 + 4x3  3x4 subject to x1 + x2 + x3 = 4 x1 + 4x2 + x4 = 8 x1, x2, x3, x4  0 using x3 and x4 as starting variables, the optimal tableau is given as basic x1 x2 x3 x4 solution z 2 0 0 3 16 x3 0.75 0 1 -0.25 2 x2 0.25 1 0 0.25 2 write the associated dual problem and determine its optimal solution