Im unsure how to do this on a TI-83 calc. It's a profit equation giving a table looking like this. How do you solve?
shirt sales for summer X Price per shirt P
500 $13.50
900 11.50
1300 9.5
1700 7.5
2100 5.5
2500 3.5

Hello MikeyP. It seems like you may have left part of the question off your post. Looks like you've provideed a table of prices, and the corresponding number of shirts you would sell at each price (i.e. the lower the price you set, the more people are willing to buy them). Am I interpreting that correctly? Well, to determine profit you also need to know the cost to make the shirts - did they give that to you? It may be in the form of a fixed cost plus a variable cost per shirt (for example, maybe it costs $100 to set up the business and $2 to manufacture each shirt). From this data you could then determine what price to set to maximize your profit. Hope this helps.