Did I Get This – Correlation Coefficient
http://phhp-faculty-cantrell.sites.medinfo.ufl.edu/files/2013/01/qzDIG02005.swf
http://phhp-faculty-cantrell.sites.medinfo.ufl.edu/files/2013/01/qzDIG02006.swf
Hint
This document is linked from Linear Relationships – Correlation.