Reconsider Prob. 9.1-6. Starting with Russell's approximation method, interactively apply the transportation simplex method to obtain an optimal solution for this problem.
In problem


After several iterations of the transportation simplex method, a BF solution is obtained that has the following basic variables: x13 = 20, x21 = 25, x24 = 5, x32 = 25, x34 = 5, x42 = 0, x43 = 0, x45 = 20. Continue the transportation simplex method for two more iterations by hand. After two iterations, state whether the solution is optimal and, if so, why.