The Dover manufacturing Company has plants in Cleveland, Chicago, Houston, and Seattle. It ships products MX 13 from these plants to warehouses in Los Angeles, Denver, and Omaha. The freight costs per unit for shipping from Cleveland are respectively $5, $1, $0; from Chicago, $3, $2, $4; from Houston, $7, $5, $2; and from Seattle, $9, $6, $0. The plants can supply respectively 20, 10, 15, and 15 units. The needs of the warehouses are respectively 5, 10, and 15 units. a) Set up the above problem appropriate for the transportation model. b) Find the starting solution using the NW corner method (Not required to find the Final solution).