please use exel solver

11. The distribution system for the Herman Company consists of three plants, two warehouses, and four customers. Plant capacities and shipping costs per unit (in S) from each plant to cach warehouse are as follows: Warehouse N- De 4 Capacity 450 600 380 Customer demand and shipping costs per unit (in S) from cach warehouse to each customer are as follows: Customer Warehouse 2 M 4 6 Demand 300 300 300 400 a. Develop a network representation of this problem. Formulate a linear programming model of the problem. Solve the linear program to determine the optimal shipping pian