The set of bivariate observation (x_1, y_1), (x_ 2 , y_ 2 ), . ....

The set of bivariate observation $\left(\mathrm{x}_1, \mathrm{y}_1\right),$\left(\mathrm{x}_{2}, \mathrm{y}_{2}\right), \ldots . . \left(\mathrm{x}_{\mathrm{n}}, \mathrm{y}_{\mathrm{n}}\right)are such that all the values are distinct and all the observations fall on a straight line with non-zero slope. Then the possible values of the correlation coefficient between x and y are