In the 2015 federal election, 39.5% of the electorate voted forthe Liberal party, 31.9% for the Conservative party, 19.7% for theNDP, 4.7% for the Bloc Quebecois and 3.5% for the Green party.
The most recent pool as of the launch of the 2019 electioncampaign shows a tie between the Liberals and the Conservatives at33.8%. This pool was based on 1185 respondents. (a) Based on thisrecent pool, test whether this is sufficient evidence to concludethat the level of support for the conservatives has increased sincethe last election. Use the 5% level of significance and show yourmanual calculations. (b) Using recent pool data, build anappropriate 95% one-sided confidence interval for the trueproportion of support for the conservatives. Is this CI consistentwith your conclusion in a) above? (c) Would your conclusion be thesame as in a) above if you had used a 10% confidence level for thehypothesis test? (d) Now, suppose you want to estimate the nationallevel of support for the Liberals at the start of the 2019 campaignusing a 95% 2-sided confidence interval with a margin of error of 1% based on the results of the last election, what sample sizewould be required? (e) Would the sample size calculated above besufficient to estimate the support for the Bloc Quebecois withinthe same level of confidence and margin of error? If not, how manymore respondents would you need?
