7.2-7. Consider the following problem. Maximize Z= Cixi + C2X2, subject to 2x X2 0. Let xz and x4 denote the slack variables for the respective functional constraints. When c = 3, C2 = -2, b. = 30, and b2 = 10, the sim- plex method yields the final simplex tableau shown here. Coefficient of: Basic Variable Right Side Eq. z X1 X2 X3 X4 1 NXX Z X2 X1 (0) (1) (2) OO 0 1 0 OO 1 1 1 1 -2 40 10 20 1 I (a) Use graphical analysis to determine the allowable range for c, and c2. (b) Use algebraic analysis to derive and verify your answers in part (a). I (c) Use graphical analysis to determine the allowable range for b and b2. (d) Use algebraic analysis to derive and verify your answers in part (c)