An experiment is performed to assess whether a new tire wears more slowly than a standard tire. A set of 20 trucks is chosen. A new tire is placed on one of the front wheels of each truck, and a standard tire is placed on the other front wheel. Right and left positions of the two kinds of tire are randomized over the 20 trucks. The trucks are driven over varying road conditions, and then the reductions in the tread depths of the tires are measured. DS 9.2.3 contains these data values in mm. Analyze the data and present your conclusions. Why is this a paired experiment? Why did the experimenter decide to perform a paired experiment rather than an unpaired experiment?