Question

What is the best estimate for the value of r in the scatter plot?

Answer 1

From the observation of the dispersion graph it is concluded that the answer to this question is option D. r = -0.5.

The correlation coefficient "r" is a measure of the linear relationship between two random variables.

When the correlation is positive, the value of "r" is between 0 and 1. This means that when one variable increases the other too.

When the correlation is negative, the value of "r" is between -1 and 0. This means that one variable decreases as the other increases.

When there is no correlation the value of "r" is 0

In this case, the dispersion chart shows that the variable "y" decreases as the variable "x" increases. Therefore the value of "r" must be negative. Of all the options, the only one that presents a value of negative r is option D:

 r = -0.5