Two polling organizations, Harris and Gallup, report weekly on the President’s approval rating, which is expressed as a proportion of Americans who approve of the job the President is doing.
In one particular week, each organization asks $100$ randomly selected people this question. Their results are as follows:
Harris Poll: $0.57$
Gallup Poll: $0.6$
What are the mean and standard deviation of the sampling distribution of the difference of these organizations’ results?