A driver of a car stopped at a gas station to fill up his gas tank. He looked at his watch, and the time read exactly 3:40 p.m. At this time, he started pumping gas into the tank. At exactly 3:44, the tank was full and he noticed that he had pumped 15.3 gallons. What is the average rate of flow of the gasoline into the gas tank? (Round your answer to one decimal place.)