The plot shown here is the sampling distribution for the present example. As you can see, the distribution is not far from the normal distribution, although it does have some negative skew.

Assume that for the population of people applying for a job at a bank in a major city, .40 are able to pass a basic literacy test required to get the job. Out of a group of 20 applicants, what is the probability that 50% or more of them will pass? This problem involves the sampling distribution of p with π = .40 and N = 20. The mean of the sampling distribution is π = .40. The standard deviation is: