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Two variables that likely matter a lot in determining the grade students earn on

ID: 2946569 • Letter: T

Question

Two variables that likely matter a lot in determining the grade students earn on their final are the amount of time spent studying and the amount of sleep the night before the test. We are going to explore this relationship with the following data Study Hours Sleep Hours Grade 78 91 68 52 100 82 89 10 13 8 10 20 15 17 Suppose you found the following result (will not be the same as above) for the estimated regression equation: GRADE-72.88+3.7STUDY-10.2SLEEP What is the interpretation of the coefficients on STUDY and SLEEP (the 3.7 and -10.2)? Do the results make sense? Why or why not?

Explanation / Answer

The coefficient of 3.7 on STUDY implies that with 1 hour increase in study, the grade of that student increases by 3.7 on an average.

The coefficient of -10.2 on SLEEP implies that with 1 hour increase in sleep before the night of exam, the grade of that student decreases by 10.2 on an average.

The results do make sense because with increase in study hours and with more time studying the night before the exam, grades will improve. However the coefficient for SLEEP does seem too steep as sound sleep is also necessary before exam.