A hotly disputed Proposition X will be on the ballot in November elections. A poll of N1 = 100 people shows that p1 = 50% (50 people) support Proposition X. A week later, a poll of N2 = 400 people shows that p2 = 55% (220 people) support Proposition X. The local newspaper claims: Support for Proposition X grows
(i) You are unconvinced and are trying to calculate the significance p-value for the null hypothesis: that the support stays on the level 50%. You use normal approximation. What is this p?
(ii) Can you reject the hypothesis with p = .05? How about p = .01?
(iii) What minimal N2 (assuming N1, p1 and p2 are unchanged) do you need to reject the null hypothesis with p = .05?