In this section we use r to denote the value of the linear correlation coefficient. Why do we refer to this correlation coofficient as being linear?
A. The term linear refers to a straight line, and r measures the fraction of the points the best line passes trough.
B. The term linear refers to a straight line that passes through the average values of the paired data, and r measures how well a scatterplot fits a straight-line pattem
C. The term linear refers to a straight line, and r measures how well a scatterplot fits a straight-line pattern
D. The term linear refers to the straight line that passes through the greatost number of points, and r meansures the fraction of the points the line passes through

In statistics, when two variables are being investigated, the location of the co-ordinates on a rectangular co-ordinates ystem is called a scatter diagram.

The amount of linear correlation between two variables is expressed by a coefﬁcient of correlation, given the symbol r. This is deﬁned in terms of the deviations of the co-ordinates of two variables from their mean values and is given by the product-moment formula

For linear correlation, if points are plotted on a graph and all the points lie on a straight line, then perfect linear correlation is said to exist. When a straight line having a positive gradient can reasonably be drawn through points on a graph positive or direct linear correlation exists.