3 Dual PriceZ=W Z is the dollars and W should also be the dollars. W= ∑bi yi bi represents the number of units available of resource i. Therefore Dollars= unit of resource i X yi Hence yi= dollars/unit of resource I So yi or dual price or shadow price of a resource I is the worth per unit of resource i.
4 Dual PriceEach dual price is associated with a constraint. It is the amount of improvement in the objective function value that is caused by a one-unit increase in the RHS of the constraint.It is also called Shadow Price.
5 More on Dual Price:A dual price can be negative, which shows a negative ( or worse off) contribution to the objective function value by an additional unit of RHS increase of the constraint.
6 Primal and Dual in LPEach linear program has another associated with it. They are called a pair of primal and dual.Primal and dual have equal optimal objective function values.The solution of the dual is the dual prices of the primal, and vice versa.