Consider a transportation problem identical to the one given in Exercise 17. One way the model may be formulated is as a linear program with inequality constraints. The formulation and solution are given below.
For this formulation of the model:
a) Are the optimal values of the shadow prices unique?
b) Determine the ranges on the righthand-side values, changed one at a time, for which the basis remains unchanged.
c) Reconcile the results of (b) with those obtained in Exercise 17.