r always denotes the direction of the relationship.
]]>r = –1.5 has to be an error.
]]>X from centimeters to feet, will the value of r change?
]]>X from diameter to volume and we change *Y* from volume to diameter, will the value of r change?
]]>r as a measure of the relationship between *X* and *Y* is misleading for the data in the above scatterplot.
]]>r is resistant to outliers.
]]>