Estimating the standard error
The most important parameter of the distribution of p2 − p1 is its standard deviation. This is also the standard deviation of the estimation error when p2 − p1 is used to estimate π2 − π1 — the standard error of the estimate.
Confidence interval for difference
A 95% confidence interval for π2 − π1 can be found from the standard error of p2 − p1.
Examples
95% confidence intervals are now found for a few examples.