Sample size to estimate proportions
Use this calculator to find the minimum sample size required to estimate proportions $p_1-p_2$.
| Sample size to estimate proportions | ||
|---|---|---|
| Confidence Level ($1-\alpha$) | ||
| Proportion of success ($p_1$) | ||
| Proportion of success ($p_2$) | ||
| Margin of Error ($E$) | ||
| Results | ||
| Z value: | ||
| Required Sample Size : ($n$) | ||
Sample size required to estimate proportions
The minimum sample size required to estimate the proportions $p_1-p_2$ is
$$ n =\big[p_1*(1-p_1)+p_2*(1-p_2)\big]\bigg(\frac{z}{E}\bigg)^2 $$
where
- $p_1$ is the proportion of successes in first group,
- $p_2$ is the proportion of successes in second group,
- $z$ is the $Z_{\alpha/2}$ and
- $E$ is the margin of error.
