7. You want to design a poll for one YesorNo question, to which the fraetionfof the total population say Yes. (a) Let X,- be equal to 1 if the ith person polls Yes, and 0 if No. Denote Mn as the sample mean of Xi's with sample size n. Assuming that all Xj's are i.i.d., what are the mean and variance of Mn? (b) Given that P(|Z|}l.96) = 0.05 for a standard normal random variable Z, what is the minimum number of the poll size to guarantee the 95% condence of less than 1% error? (C) Now you do not have access to the standard normal distribution table, and should instead use the Chebyshev's inequality 2 FOXu 1:0)3 02 C What is the minimum number of the poll size to guarantee the 95% condence of less than 1% error