71 1 point Suppose you open a small business selling custom made shirts for school sporting teams. You estimate that your monthly fixed costs will be comprised of 5516 for rent, $97 for utilities, $29 for insurance, S46 for permits, and $128 for transportation. If the average cost of materials necessary to produce each shirt (variable costs $6 and you were able to sell each shirt for $18, How many shirts will you have to sell each month before you start to make a profit