What is remarkable about this quartet is that for all of these scatter plots the mean of

*x*is the same (exactly), the variance of

*x*is the same (exactly), the mean of

*y*is the same (to two decimal places), the variance of

*y*is the same (to three decimal places), the correlation between

*x*and

*y*is the same (to three decimal places), and the linear regression equation is the same (to two or three decimal places). In other words, the models of the data (e.g., mean, variance, correlation, etc.) are the same, but the data are not!

So what's the solution? As I've mentioned in previous posts, graphing the data is crucial, because we're forced to confront the actual data, and not models of the data.