The variable cost (in dollars) of producing each box is equal to the box's volume. A fixed cost of $1,000 is incurred to produce any quantity of a particular box. If the company desires, demand for any type of box can be satisfied by a box of a larger size. Formulate but do not solve an IP model to determine the minimum cost of meeting the demand for boxes. Be sure to define your decision variables. Your objective function and constraints must be linear functions; do not multiply decision variables by each other