John Smith makes handcrafted dolls, which he sells at craft fairs. He is considering mass production the dolls to sell in stores. He estimates that the initial investment for plant and equipment will be $25000, whereas labor, material, packaging, and shipping will be about $15 per doll. If the dolls are sold for $30 each.

Write a math model for total cost., Write a math model for total revenue., Write an expression for total profit., Find the break-even point.