International Journal of Mathematics and Mathematical Sciences
Volume 13 (1990), Issue 4, Pages 799-805

The effect of a single point on correlation and slope

David L. Farnsworth

Department of Mathematics, Rochester Institute of Technology, Rochester 14623, New York, USA

Received 8 December 1989; Revised 27 April 1990

Copyright © 1990 David L. Farnsworth. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


By augmenting a bivariate data set with one point, the correlation coefficient and/or the slope of the regression line can be changed to any prescribed values. For the target value of the correlation coefficient or the slope, the coordinates of the new point are found as a function of certain statistics of the original data. The location of this new point with respect to the original data is investigated.