2. (20 points) For this problem, just show the formulation. There is no need to solve it in Solver. A multi-echelon distribution system consists of two factories, three regional warehouses, and three retailers. Production costs are $6.00 per unit at factory 1 and $6.30 per unit at factory 2. Costs of shipping from the factories to the regional warehouses are given in Table 1, and costs of shipping from the warehouses to the retailers are given in Table 2. Factory 1 can produce up to 5000 units per month and factory 2 up to 3400 units per month. The three retailers require at least 2100, 3600, and 1800 units per month, respectively. You must decide how much to produce and ship to each regional warehouse from each factory, and how much to ship from each regional warehouse to each retailer to minimize total monthly costs. Factory 1 Factory 2 Warehouse 1 Warehouse 2 Warehouse 3 $1.02 $1.08 $0.86 $0.96 $0.95 $1.03 Table 1. Shipping Cost per Unit from Factory to Warehouses Retailer 1 Retailer 2 Retailer 3 Warehouse 1 $0.25 $0.44 $0.46 Warehouse 2 $0.36 $0.41 $0.50 Warehouse 3 $0.34 $0.45 $0.47 Table 2. Shipping Cost per Unit from Warehouse to Retailers