At the county 4th of July fair, a local strong man challenges contestants two at a time to a tug-of-war contest. Contestant A can tug with a force of 390 pounds. Contestant B can tug with a force of 320 pounds. The angle between the ropes of the two contestants is 30. With how much force must the local strong man tug so that the rope does not move? The strong man must tug with approximately pounds of force. (Round to one decimal place as needed.)