Probability plots
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A probability plot displays the percentiles. You can use the probability plot to assess whether a particular distribution fits your data. In general, the closer the points fall to the fitted line, the better the fit.

When you have more than one factor level, lines and confidence intervals are drawn for each level. If the plot looks cluttered, you can turn off the confidence intervals in the Graphs subdialog box. You can also change the confidence level for the 95% confidence by entering a new value in the Estimate subdialog box.