Traffic speed: The mean speed for a sample of 38 cars at a certain intersection was 25.96 kilometers per hour with a standard deviation of 2.54 kilometers per hour, and the mean speed for a sample of 140 motorcycles was 34.71 kilometers per hour with a standard deviation of 3.96 kilometers per hour. Construct a 95% confidence interval for the difference between the mean speeds of motorcycles and cars at this intersection. Let u, denote the mean speed of motorcycles and round the answers to at least two EO decimal places. A 95% confidence interval for the difference between the mean speeds, in kilometers per hour, of motorcycles and cars at this intersection is