Question

Which of the following is the best answer to the question "Would a sample proportion of 0.3 be considered unusual for a sample of size 908 if the true proportion is 0.224?" Yes, because the probability is less than 0.05. Yes, because the probability is more than 0.05. No, because the probability is less than 0.05. No, because the probability is more than 0.05.

Answer 1

z = (pcap - p)/sqrt(p*(1-p)/n)
z = (0.3 - 0.224)/sqrt(0.224*(1-0.224)/908)
z = 5.49

P(z > 5.49) = 0.0000

Hence this is unusual because the probability is less than 0.05

Option A