Final answer:
The correlation coefficient of +0.2 represents the weakest association between X and Y variables because it is the value closest to zero.
Step-by-step explanation:
The correlation coefficient represents the strength and direction of a linear relationship between two variables. It ranges from -1 to +1, where a value close to +1 indicates a strong positive linear relation, a value close to -1 indicates a strong negative linear relation, and a value close to 0 indicates no linear relation. In this case, the options given are +.2, +.6, -0.5, and -0.9.
To determine which correlation coefficient represents the weakest association, we look for the value closest to zero. Thus, the correlation coefficient of +0.2 represents the weakest linear relationship between the X and Y variables because it is the value closest to zero compared to the other options provided.