Calculate Sample Size for Two Proportions
Introduction & Importance
Calculating sample size for two proportions is crucial in statistical studies to ensure the results are reliable and valid…
How to Use This Calculator
- Enter the proportions for Group 1 and Group 2.
- Enter the standard deviation and desired power.
- Click ‘Calculate’.
Formula & Methodology
The sample size calculation is based on the formula…
Real-World Examples
Example 1: A pharmaceutical company wants to compare the effectiveness of two drugs…
Data & Statistics
| Power | Sample Size (n) |
|---|---|
| 0.8 | 78 |
| 0.9 | 106 |
Expert Tips
- Always round up the calculated sample size to the nearest whole number.
- Consider using a power of 0.8 or 0.9 for most studies.
Interactive FAQ
What is power in sample size calculation?
Power is the probability that a test will reject the null hypothesis when the alternative hypothesis is true…
CDC’s Sample Size Calculation and UNC’s Sample Size Calculation Guide are excellent resources.