SAT OwlQuestion bank / Command of Evidence
| Hours of sleep the previous night | Average reaction time (milliseconds) | Errors per 100 trials |
|---|---|---|
| 4 | 412 | 9.1 |
| 6 | 361 | 5.4 |
| 8 | 318 | 3.2 |
| 10 | 320 | 3.0 |
Researchers measured how quickly participants responded to a signal after different amounts of sleep. They concluded that more sleep improved reaction time up to about 8 hours, beyond which additional sleep produced little further improvement.
Which choice most effectively uses data from the table to support the researchers' conclusion?
Participants made 9.1 errors per 100 trials after 4 hours of sleep, the most of any group.
Average reaction time after 6 hours of sleep was 361 milliseconds, faster than after 4 hours of sleep.
Participants made fewer errors after 10 hours of sleep than after any other amount of sleep.
Average reaction time fell from 412 milliseconds after 4 hours of sleep to 318 milliseconds after 8 hours but stayed about the same, at 320 milliseconds, after 10 hours.
Show answer and explanation
Answer: D
The conclusion has two parts: reaction time improves up to 8 hours, then levels off. Choice D shows the drop from 412 to 318 milliseconds and then almost no change at 10 hours (320). Choices A and C concern errors, not reaction time.
Choice B shows improvement between 4 and 6 hours but says nothing about the leveling off after 8 hours.
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