Difference between two proportions
This simulation shows that the difference between sample proportions, p2 - p1, is a random quantity and shows the theoretical normal approximation to its distribution.
Firstly take a few samples and observe the variability in the sample counts. Click the checkbox Proportions to show the variability of the proportions and their difference.
p2 - p1 varies from sample to sample and is often not equal to the population difference, π2 - π1.
Click Accumulate then take several samples to build up the empirical distributions of the individual proportions and their difference.
The normal distributions are the theoretical normal approximations. In particular,