please do 12 a and 12b

12. Mrs. Bracken asks a random sample of 500 adults whether they favor giving vouchers to parents of school- age children that can be exchanged for education at any public or private school of their choice. Each school would be paid by the government on the basis of how many vouchers it collected. Suppose that 45% of the population favor this idea. (a) What is the mean of the sampling distribution of p , the proportion of adults in samples of size n = 500 who favor giving parents of school-age children these vouchers? (!) (b) What is the standard deviation of p ? Interpret this value. (R)