Random samples of size n were selected from binomial populat

Random samples of size n were selected from binomial populations with population parameters p given here. Find the mean and the standard deviation of the sampling distribution of the sample proportion ha p in each case. (Round your answers to four decimal places.) (a) n = 900, p = 0.3 mean standard deviation (b) n = 400, p = 0.9 mean standard deviation (c) n = 260, p = 0.6 mean standard deviation

Solution

a)

mean =0.3

sd = sqrt(p*(1-p)/n) = sqrt(0.3*0.7/900) =0.0153

b)

mean =0.9

sd = sqrt(0.9*0.1/400) =0.0150

c)

mean =0.6

sd = sqrt(0.6*0.4/260) =0.0304