Julie finds that the number of hours she sleeps each night is related to the scores she receives on quizzes the next day. As her sleep approaches 8 hours, her quiz scores improve; as her sleep drops to 5 hours, her quiz scores show a similar decline. Julie realizes that ________.
A) there is a negative correlation between the number of hours she sleeps and her quiz grades
B) there is a positive correlation between the number of hours she sleeps and her quiz grades
C) her low quiz scores are caused by sleep deprivation the night before a quiz
D) she should sleep about 10 hours a night to ensure 100 percent quiz grades

Question

Julie finds that the number of hours she sleeps each night is related to the scores she receives on quizzes the next day. As her sleep approaches 8 hours, her quiz scores improve; as her sleep drops to 5 hours, her quiz scores show a similar decline. Julie realizes that ________.
A) there is a negative correlation between the number of hours she sleeps and her quiz grades 
B) there is a positive correlation between the number of hours she sleeps and her quiz grades 
C) her low quiz scores are caused by sleep deprivation the night before a quiz
D) she should sleep about 10 hours a night to ensure 100 percent quiz grades

Quizplus · Accepted Answer

The passage states that as Julie's sleep approaches 8 hours, her quiz scores improve, and as her sleep drops to 5 hours, her quiz scores decline. This indicates a positive correlation between the number of hours she sleeps and her quiz grades. Option A is incorrect because a negative correlation would mean that as the number of hours of sleep decreases, the quiz scores increase, which is not the case here. Option C is incorrect because the passage does not state that sleep deprivation causes low quiz scores; it only indicates that the amount of sleep Julie gets is related to her quiz scores. Option D is incorrect because there is no evidence in the passage to support the claim that Julie needs to sleep for 10 hours to get 100 percent quiz grades.

Julie Finds That the Number of Hours She Sleeps Each