The process of modeling using linear programming is fairly consistent: define the decision variables, objective, and constraints.

**Decision Variables.** In this case, the decision variables are
the number of units of each outlet to purchase. Let be the
number of TV spots, and the number of magazine pages.

**Objective.** Our objective is to minimize the amount we spend: .

**Constraints.** We have one constraint for each market segment:
we must be certain that we reach sufficient people of each segment.
For boys, this corresponds to the constraint:

Similar constraints for the other segments gives us the full formulation as:

Mon Aug 24 14:40:57 EDT 1998