posted by cortez on .
In the media, numerous surveys are often displayed reporting percentages or proportions. A margin of error is often reported in the survey and this is used to calculate confidence intervals. Why is it important to create/report confidence intervals (CI) rather than just reporting the averages or proportions? is it better to use 95% confidence interval or 99% confidence interval?
The CI gives some indication of how accurate the data is. Do you believe the 4% difference is important?