Discussion: Applying Confidence Intervals to Make Predictions
One of the most common uses of confidence intervals is found in political polls and the news articles that reference them. These articles often use the point estimate (the proportion), and you can usually find the margin of error (half of the confidence interval) somewhere in the article as well. For example, consider the following scenario:
Two separate polling organizations have conducted polls for two candidates who are running for state senate, Gail Schultz and Raymond McGregor. The polls were taken from the same population, in the same state, and on the same day.
The survey from the first company, Pollster Analytics, shows Gail having 49% of the potential vote. It also shows Raymond having an estimated 47% of likely voters. Both results reflect a margin of error of 2 percentage points (usually depicted as ±2%).
The survey from the second company, Polltastik, shows Raymond at 49% and Gail at 46%. This survey has a 3-percentage-point margin of error (±3%).
In this Discussion, you will compare the outcomes of the surveys in the scenario and apply the concept of confidence intervals to make a prediction for the upcoming election, as well as discuss their implications.
To prepare for this Discussion:
- Review this week’s Learning Resources.
- Refer to the scenario described above and consider who is ahead in the race and why.
- Review the Academic Writing Expectations for 2000/3000-Level Courses, provided in this week’s Learning Resources.
By Day 3
Post a 75- to 150-word (1- to 2-paragraph) explanation of how you applied confidence intervals to make predictions about the outcome of a political campaign. In your explanation, address the following:
- After reviewing both polls, what is now known about who might be ahead in the race? Explain who is ahead and why.
- Explain what the implications of these polls are for the campaign managers for Gail and Raymond.
- To support your response, be sure to reference at least one properly cited scholarly source.
By Day 5
Respond with at least 75 words (1 paragraph) each to two or more of your colleagues’ postings by doing one of the following:
- Compare your conclusion to your colleague’s answer to the question of who is ahead in the race. Make note of any similarities or differences in your conclusions, including the reasons why.
- Explain whether you agree or disagree with your colleagues on what the implications of the polls are. Did you find resources or articles that help expand on what your colleague has written?