7-90. The data file Trucks contains data on a sample of 200 trucks that were weighed on two scales. The WIM ( weigh-in-motion) scale weighs the trucks as they drive down the highway. The POE scale weighs the trucks while they are stopped at the port-of-entry station. The maker of the WIM scale believes that its scale will weigh heavier than the POE scale 60% of the time when gross weight is considered