Which of the following correlation coefficients represents the weakest relationship between two quantitative variables?

The correlation coefficient measures the strength and direction of a linear relationship between two quantitative variables. It ranges from -1 to 1, where values closer to -1 indicate a strong negative relationship, values close to 1 indicate a strong positive relationship, and values around 0 suggest a weak or no relationship at all.

In this scenario, a correlation coefficient of 0.15 indicates a very weak positive relationship between the two variables. This suggests that as one variable increases, there is only a slight tendency for the other variable to increase as well, making the relationship practically negligible.

On the other hand, coefficients like -0.80, 0.70, and -0.50 indicate much stronger relationships. The first two represent strong connections (one negative and the other positive), and -0.50 indicates a moderate negative relationship. Hence, 0.15 stands out as the weakest correlation coefficient among the options provided, confirming that it reflects the least substantial association between the two quantitative variables.