One of the cylinders of an automobile engine has a volume of 400. cm³. The engine takes in air at a pressure of 1.00 atm and a temperature of 15°C and compresses the air to a volume of 50.0 cm³ at 77°C. What is the final pressure of the gas in the cylinder? (The ratio of before and after volumes— in this case, 400∶50 or 8∶1—is called the compression ratio.)