Using the Density Ellipse option, you can draw an ellipse (or ellipses) that contains the specified mass of points. The number of points is determined by the probability that you select from the Density Ellipse menu).
Example of Density Ellipses
The density ellipsoid is computed from the bivariate normal distribution fit to the X and Y variables. The bivariate normal density is a function of the means and standard deviations of the X and Y variables and the correlation between them. The Other selection lets you specify any probability greater than zero and less than or equal to one.
The Correlation report that accompanies each Density Ellipse fit shows the correlation coefficient for the X and Y variables.
Note: To see a matrix of ellipses and correlations for many pairs of variables, use the Multivariate command in the Analyze > Multivariate Methods menu.
 Variable Gives the names of the variables used in creating the ellipse Mean Gives the average of both the X and Y variable. Std Dev Gives the standard deviation of both the X and Y variable. Correlation The Pearson correlation coefficient. If there is an exact linear relationship between two variables, the correlation is 1 or –1 depending on whether the variables are positively or negatively related. If there is no relationship, the correlation tends toward zero. Signif. Prob Number Gives the number of observations used in the calculations.
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