Base your answer on Your teacher brings two bags of colored goldfish crackers to class. Bag 1 has 25% red crackers and Bag 2 has 35% red crackers. Each bag contains more than 1000 crackers. Using a paper cup, your teacher takes an SRS of 50 crackers from Bag 1 and a separate SRS of 40 crackers from Bag 2. Let p1^ - p2^ be the difference in the sample proportions of red crackers. Assume the shape is approximately normal. Find the mean of the sampling distribution of p^(b2)-p^(b1) .