Question 2 of 8 (1 point) | Attempt 1 of Unlimited 10.1 Section Exer Traffic speed: The mean speed for a sample of 40 cars at a certain intersection was 25.40 kilometers per hour with a standard deviation of 2.17 kilometers per hour, and the mean speed for a sample of 149 motorcycles was 39.55 kilometers per hour with a standard deviation of 3.40 kilometers per hour. Construct an 80% confidence interval for the difference between the mean speeds of motorcycles and cars at this intersection. Let it denote the mean speed of motorcycles and round the answers to at least two decimal places. An 80% confidence interval for the difference between the mean speeds, in kilometers per hour, of motorcycles and cars at this intersection is