Two different simple random samples are drawn from two different populations. The first sample consists of 40 people with 22 having a common attribute. The second sample consists of 2000 people with 1420 of them having the same common attribute. Compare the results from a hypothesis test of p1=p2 (with a 0.01 significance level) and a 99% confidence interval estimate of p1-p2.

Identify the test statistic.