Hi everyone,

i need help finding E(p1-p2) And Var(P1-P2) where p1=X1/n1 where n1 is a sample from group 1 that yielded X1 successes and p2=X2/n2 where n2 is a sample from group 2 that yielded X2 successes. I.E find the expected value and variance for the difference between two population proportions.