Making Inferences and Justifying Conclusions: Evaluating Reports Based on Data (CCSS.S-IC.6) Practice Test

In a randomized study, 50 algebra students were split into two groups. Twenty-five used an online practice program; 25 did regular homework. After six weeks, the program group averaged 78 on the unit test, while the regular group averaged 72. The teacher wrote: "The program causes higher scores everywhere, so the district should buy it for all classes. Also, students who used the program will get A's on the final."

A city transportation survey asked 1,000 residents about their commute. Of those, 120 reported biking to work at least three days per week. The report suggests that adding bike lanes will definitely reduce car traffic citywide.