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 table below. 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 $8 $5 E $3 $6 $7 $7 380 Y 300 C $5 $6 Z 400