Difference in Proportion Confidence Interval Calculator
Difference in proportion confidence intervals are crucial in statistics to compare two proportions and determine if the difference is statistically significant.
- Enter the sample size.
- Select the desired confidence level.
- Input the two proportions you want to compare.
- Click ‘Calculate’.
The formula used is based on the Wilson score interval for two proportions:
Z * √[(p1 * (1 – p1) / n1) + (p2 * (1 – p2) / n2)]
| Confidence Level | Interval Width |
|---|---|
| 90% | 1.645 |
| 95% | 1.960 |
| 99% | 2.576 |
- Always ensure your sample sizes are large enough for accurate results.
- Consider the context and implications of your results.
What is a confidence interval?
A confidence interval is a range of values around a sample statistic (like a mean or proportion) that indicates the reliability of the statistic.
For more information, see the CDC’s guide on confidence intervals and the Introductory Statistics textbook.