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A researcher wanted to see if there was an association between the number of hours spent watching TV and students’ grade point averages. He found . Interpret the researcher’s results.

r represents the correlation coefficient.
Review the Math Notes box in section 4.2.4

Since is negative, there is a decreasing association (the slope is negative) between the hours spent watching TV and GPA.
The closer is to or , the closer to perfectly linear the association is.
-squared represents the percentage of variability that can be attributed to the dependent variable.

Therefore, there is a good, but not great association between these two variables, meaning as the number of TV watching hours increases, the GPA of the student tends to decrease.
Since -squared , so % of the variability in GPA can be attributed to hours of TV watched.
Any other variability should be attributed to other factors.