2. (7 pts) The distribution system for the Smith Company consists of three plants (A, B, and C), two warehouses (D and E), and four customers (W, X, Y, and Z). The relevant supply, demand, and unit shipping cost information are given in the following table. Set up and solve the transshipment model to minimize total shipping costs. TO TO PLANT SUPPLY CUSTOMER DEMAND FROM D E FROM W X Y Z A 450 W 450 A $4 $7 D $6 $4 $8 $4 B 500 X 300 B $5 E $3 $7 $7 380 Y 300 C $5 $6 7. 400 Please formulate the problem (identify the decision variables, the objective, and the constraints) and then solve the problems with Excel