58. A manufacturer can produce cell phone cases that retail for $9 each, and at that price, they are selling 3000 cases a month. The manufacturer is planning to raise the price of the cases and has market studies that indicate for each $1 increase in the price, 300 fewer will be sold each month. a) Make a table of possible values for number sold and profit. Be sure to include critical (important) values in your table. x price # sold 3000 y revenue 27000 b) What is the vertex? Sketch the data (price, revenue) if needed. c) Write a function for revenue using the graph you created. Hint: You need to find the "a" value first using the vertex and any other point