# Statistics > Confidence Intervals > 2-Population Proportion

This utility computes confidence intervals for the difference of two population proportions. The confidence interval estimate of p1 - p2 is:

where the margin of error E is given by , is the sample proportion, and .

### Dialog Inputs

The sample data of the population must be of only two categories. They can be inputted in one of three ways:

- Samples in one column: The population labels of samples are in one column of the Datasheet, and the individual samples are in another column.
- Samples in two columns: The samples of the two population are in two separate columns.
- Summarized sample data: The number of events and the number of trials of each of the two populations are provided (instead of individual sample values).

The confidence level must be between 0 and 1. For example, enter 0.95 for a 95% confidence level.