Practice Test 9

An environmental agency reports that after a factory installed a new filtration system, measured particulate pollution within one kilometer of the factory fell by 30% relative to the previous year. The agency concludes that requiring the same filtration system at similar factories will reduce particulate pollution across the region. Which of the following best bolsters the author’s reasoning?

A school district introduced a later start time for high school students. In the first year, the average number of student absences per semester decreased from 6.1 to 5.4. The superintendent concludes that later start times reduce absences and recommends adopting the later start time for all middle schools as well. Which of the following, if true, most strengthens the argument?