A transport office's note reads: 'Of the vehicles booked for overloading at the district's check gates last year, 70 in every hundred were tractor-trailers. It follows that most of the tractor-trailers on the district's roads run overloaded.' The note's reasoning is most open to criticism because it

The figure describes the small basket of vehicles that were booked; the conclusion describes the great mass of trailers on the roads. Seven hundred trailers booked out of a thousand bookings is consistent with fifty thousand trailers running the district's roads, of which one in seventy was ever booked. The note supplies no denominator and so cannot get from the one claim to the other. Whether a booking was rightly made is a separate question that would not repair the step; the fine and the choice of year leave the reversal untouched.