Waterways packages some of its products into sets for home installations. One set's (small) unit selling price is $77 with unit variable costs of $50. Another set's (large) unit selling price is $149 with unit variable costs of $101. The parts for the $77 set take 9 machine hours to produce. The parts for the $149 set take 20 machine hours to produce. Given the information above, and assuming all of the package sets produced can be sold each month, illustrate the best use of machine hours. (Round answers to 2 decimal places, e.8. 5.25.) The is the best use of a limited resource. Contribution margin per unit of limited resource $ is the best use of a limited resource