Enter the level of confidence for the confidence interval that is displayed on the fitted line plot.
Usually, a confidence level of 95% works well. A 95% confidence level indicates that, if you took 100 random samples from the population, the confidence intervals for approximately 95 of the samples would contain the parameter that the interval estimates. For a given set of data, a lower confidence level produces a narrower interval, and a higher confidence level produces a wider interval.
To display the confidence interval, you must go to the Graphs subdialog box, and under Binary fitted line plot, select Display confidence interval.