The imperial flack jacket company currently ships all products out of two factories (a and b) to two government warehouses. because of increasing demand, another factory will have to be built. the company has two possible locations in mind (c or d) and is currently trying to choose between them using the linear programming (lp) transportation method. data on monthly shipping and receiving volumes and per‑unit shipping costs are: factory warehouse 1 warehouse 2 production capacity existing a $2.80 $3.45 2,000 existing b $2.50 $4.10 3,500 proposed c $3.25 $3.10 4,000 proposed d $2.95 $3.55 4,000 min. demand 5,000 4,000 how many decision variables are involved in either lp formulation (i. e., with using either proposed location c or d excluding the non-negativity constraint)?