A Gallup Poll asked a sample of Canadian adults if they thought the law should allow doctors to end the life of a patient who is in great pain and near death if the patient makes a request in writing. The poll included 270 people in Quebec, 221 of whom agreed that doctor assisted suicide should be allowed.
(a) What is the margin of error of the large-sample 95% confidence interval for the proportion of all Quebec adults who would allow doctor assisted suicide?
(b) How large a sample is needed to get the common +(line underneath +) 3 percentage point margin of error?
Step by step method for testing the hypothesis under 5 step approach is discussed here.