A company manufactures a product at its plants in C and D; then ships the product to its four distribution centers in K, L, M, and N. The transportation costs per unit (in dollars per unit) are as follows: from C to K, L, M, and N: 10, 3, 5, and 7. from D to K, L, M, and N: 8, 6, 8, and 10. The monthly demand from K, L, M, and N are: 4400, 2600, 5600, and 2500 units, respectively. On the other hand, the monthly capacity at plants C and D are: 5500 and 9800 units, respectively. Develop a linear programming model that can be used to determine the distribution plan that will minimize total monthly transportation cost. Use Excel Solver to find the optimal solution The optimal solution shows that the total monthly transportation cost is __________ dollars.