medium · SAT Reading & Writing

A cognitive-science team studying adolescent sleep surveyed five groups of high school students, each defined by average nightly sleep, and measured each group's average reaction time on a timed task. Hypothesis: Adolescents who sleep fewer hours per night show slower average reaction times. Graph 1. Average Nightly Sleep vs. Average Reaction Time Average Nightly Sleep (hours): 6 7 8 9 10 Average Reaction Time (ms): 310 290 265 250 252 Which choice most effectively uses data from the graph to illustrate the researchers' hypothesis?

1. The data show that reaction time will keep improving without limit for every additional hour of sleep beyond ten hours.
2. Each of the five sleep-duration groups in the study contained more than 40 adolescent participants.
3. Students averaging 6 hours of sleep had a 310 ms reaction time vs. 250 ms at 9 hours — less sleep, slower reaction.
4. The graph shows that reaction time became consistently slower as average nightly sleep increased from 6 to 10 hours.

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