Consider the following scatterplot of two variables x and y. We may conclude:
A)the correlation between x and y must be close to 1, because there is a nearly perfect relation between them.
B)the correlation between x and y must be close to -1, because there is a nearly perfect relation between them but it is not a straight line relation.
C)the correlation between x and y is close to 0 because, although there is a strong relationship between these variables, it isn't a linear relationship.
D)the correlation between x and y could be any number between -1 and +1; we can say nothing more without knowing the actual values.

Question

Consider the following scatterplot of two variables x and y.  We may conclude:
A)the correlation between x and y must be close to 1, because there is a nearly perfect relation between them. 
B)the correlation between x and y must be close to -1, because there is a nearly perfect relation between them but it is not a straight line relation. 
C)the correlation between x and y is close to 0 because, although there is a strong relationship between these variables, it isn't a linear relationship. 
D)the correlation between x and y could be any number between -1 and +1; we can say nothing more without knowing the actual values.

Quizplus · Accepted Answer

Although there is a clear pattern in the scatterplot (as x increases, y generally increases), the relationship is not a straight line, and therefore the correlation is not perfect. It is important to note that correlation measures only linear relationships, so even though there may be a strong relationship between x and y, it would not necessarily result in a correlation coefficient close to 1.

Consider the Following Scatterplot of Two Variables X and Y