In each of the following cases, find the mean, variance, and standard deviation of the sampling distribution of the sample proportion ? . (a) p= .5, n= 250 (Round variance to 6 decimal places and standard deviation to 4 decimal places. Do not round intermediate values.) H(p-hat) = p 0.5 o(p-hat)^2 o(p-hat) (b) p= 1, n= 100 (Round variance to 6 decimal places and standard deviation to 4 decimal places. Do not round intermediate values.) H(p-hat) = p 0.1: o(p-hat)^2 o(p-hat)(c) p = .8. n = 400 (Round variance to 6 decimal places and standard deviation to 4 decimal places. Do not round intermediate values.) (d) p = .98, n = 1,000 (Round variance to 6 decimal places and standard deviation to 4 decimal places. Do not round intermediate values.)