Janie has found 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. janie realizes that:

   There is a positive correlation between the number of hours she sleeps and her quiz grades

Explanation:  Sleep is very important for normal functioning during the working day and for performing often difficult daily tasks. The number of hours required to sleep varies by age and varies from person to person, though not much. In healthy adults, sleep should be no less than 6-7 hours and up to 9 hours of sleep during the night. Even more in children. Failure to sleep can affect the outcome of daily appointments, obligations, duties, as well as the outcomes of student obligations such as tests and grades, in a bad way, of course. Well-slept Janie, like all of us, is much more successful when she sleeps well, which is more than five hours. So good sleep is directly related to daily performance in all fields.