Answer Happy

Traffic speed: The mean speed for a sample of 36 cars at a certain intersection was 28.46 kilometers per hour with a standard deviation of 2.58 kilometers per hour, and the mean speed for a sample of 133 motorcycles was 40.89 kilometers per hour with a standard deviation of 3.46 kilometers per hour. Construct a 90% confidence interval for the difference between the mean speeds of motorcycles and cars at this intersection. Let μ, denote the mean speed of motorcycles and round the answers to at least two decimal places A 90% confidence interval for the difference between the mean speeds, in kilometers per hour, of motorcycles and cars at this intersection is <H₁-H₂