A

**confidence interval for a difference in proportions**is a range of values that is likely to contain the true difference between two population proportions with a certain level of confidence.The formula to calculate the confidence interval is:

Confidence interval = (p

_{1}– p_{2}) +/- z*√(p_{1}(1-p_{1})/n_{1}+ p_{2}(1-p_{2})/n_{2})where:

- p
_{1}, p_{2}: sample 1 proportion, sample 2 proportion - z: the z-critical value based on the confidence level
- n
_{1}, n_{2}: sample 1 size, sample 2 size

To find a confidence interval for a difference between two population proportions, simply fill in the boxes below and then click the “Calculate” button.

95% C.I. = [0.0236, 0.2964]

You can be 95% confident that the interval [0.0236, 0.2964] contains the true difference between the population proportions.