The correlation coefficient r describes the direction and strength of a linear relationship between two quantitative variables. Its values range from −1 to +1. A negative value indicates that as one variable increases, the other tends to decrease. Since r = −0.5, the direction is negative. Its magnitude, 0.5, is not close enough to zero to indicate no relationship, but it is also not close enough to −1 to represent an extremely strong relationship. Therefore, the best description is a moderate negative linear relationship. Option B is incorrect because the sign is negative, not positive. Option C is incorrect for both direction and strength. Option D would be appropriate only when r is near 0, indicating little or no linear association. A scatterplot with r = −0.5 would generally show a downward trend, but with noticeable scatter around the trend. Study Guide references/topics: correlation coefficient, negative association, scatterplots, linear relationship strength.

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