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Confidence Interval for a Difference in ProportionsStatLens

Choose a dataset:

Paste data (CSV with group and outcome columns):

Open a CSV, TSV, or JSON file:

Group 1 Group label: Successes: Sample size (n₁):

Group 2 Group label: Successes: Sample size (n₂):

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Grouping variable: Outcome variable:

Count as success:

Confidence level

Confidence level % — or drag the critical values on the plot

Select a dataset or enter summary statistics — the interval appears automatically.

Testing a hypothesis? Two-Proportion z-Test →

Keyboard Shortcuts

Estimate the difference between two population proportions with a confidence interval. Set the confidence level (or drag the critical values on the plot) and read the interval.

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