A companys old antacid formula provided relief for 70 of the

A company\'s old antacid formula provided relief for 70% of the people who used it The company tests a new formula to see if it is better and gets a P-value of 0.03. Would a 95% confidence interval for p based on this sample contain 0.7?

Solution

one sided p-value of 0.03 => 2 sided test will have p-value of 2*0.03 = 0.06, which is not less than 0.05, therefore we would fail to reject null for 2 tailed test, => 2-sided CI will contain 0.7 at 95% confidence level.