An article presents a new method for timing traffic signals in heavily traveled intersections. The effectiveness of the new method was evaluated in a simulation study. In 50 simulations, the mean improvement in traffic flow in a particular intersection was 652.6 vehicles per hour, with a standard deviation of 311.7 vehicles per hour. Find a 98% confidence interval for the improvement in traffic flow due to the new system. Round the answers to three decimal places. The 98% confidence interval is