Your boss is the project manager for a large contract assembly plant. A new customer has come to you with a product they want $25$ units of assembled. The customer estimates that the time to assemble a unit is about $15$ hours to assemble each one and is willing to pay you at that rate. She accepts the terms and offers you the project. You want to impress the boss but you don$$t want to take the project if it will lose money and make you look bad. She tells you that the first unit took $28$ hours and the second one took $21$ hours.