According to a Pew Research survey conducted in February 2014, 24% of American adults said they trust the government in Washington, D.C., always or most of the time. Suppose that this result is true for the current population of American adults. Let p̂ be the proportion of American adults in a random sample who hold the aforementioned opinion. Find the mean and standard deviation of the sampling distribution of p̂ and describe its shape when the sample size is:

a. 30 

b. 300 

c. 3000