How do drivers react to sudden large increases in the price of gasoline? To help answer the question, a statistician recorded the speeds of cars as they passed a large service station. He recorded the speeds (mph) in the same location after the service station sign showed that the price of gasoline had risen by 15 cents. Can we conclude that the speeds differ?

Speeds Before Price Increase: 43 36 31 30 28 36 27 36 35 30 32 36

Speeds After Price Increase: 32 33 36 31 32 29 28 39 26 30 32 30