## A bigger hoop is better: why confidence intervals get wider as the confidence increases

Joe, I think you are understanding confidence intervals, but I am not sure I am understanding your comments. So, let me restate them a bit. A 95% confidence interval means that if you repeat exactly the same process/experiment many times, 95% of the time the population parameter, e.g. the mean, will fall within that interval. […]

## Minimum Sample Size Calculator for Population Proportion Confidence Interval

If you are conducting a survey, you will need to decide on the number of people you need to sample. That, of course, depends upon how confident you want to be and how accurately you want to predict the population proportion based on your survey results. If you want to be 95% confident, that is […]

## Find Confidence Level, C, for Population Proportion Confidence Interval

Although we normally start with the confidence level, C, we want for our confidence interval, sometimes you need to work backwards from the margin of error, E, and find the confidence level, In this problem, you are given some summary data about a survey and asked you to find the confidence level and the confidence […]