Overloading in the trucking industry. Although illegal, overloading is common in the trucking industry. A state highway planning agency (Minnesota Department of Transportation) monitored the movements of overweight trucks on an interstate highway using an unmanned, computerized scale that is built into the highway. Unknown to the truckers, the scale weighed their vehicles as they passed over it. Each dayâ€™s proportion of 1 weekâ€™s total truck traffic (five-axle tractor truck semitrailers) is shown in the first column of the table below. During the same week, the number of overweight trucks per day is given in the second column. This information is saved in the accompanying file. The planning agency would like to know whether the number of overweight trucks per week is distributed over the 7 days of the week in direct proportion to the volume of truck traffic. Test using a = .05.