Properties of sampling distribution of difference between proportions:

1. Mean= Up

2. Variance=S

3. Variance=S

1. Mean= Up

_{1}-p_{2}= p_{1}-p_{2 Where p is probability}2. Variance=S

^{2}p_{1}-p_{2}=p_{I}q_{1}/n_{1}+p_{2}q_{2}/n_{2 }with replacement3. Variance=S

^{2}p_{1}-p_{2}=p_{1}q_{1}/n_{1}{N_{1}-n_{1}/N_{1}-1} + p_{2}q_{2}/n_{2}{N_{2}-n_{2}/N_{2}-1} without replacement_{www.ruf.rice.edu}_{ }