Statistics > Confidence Intervals > 1-Population Proportion

This utility computes the confidence intervals for a population proportion in one population using normal approximation. The confidnece intervals are calculated using the following formula:

where

n = sample size
= sample proportion
= inverse cumulative probability of the z distribution at 1 - α/2.

If the conditions for normal approximation (, ) are not met, a warning will be shown along with the results of the computation.



To use the utility, select Statistics > Confidence Intervals > 1-Population Variance.

The number of trials, number of events, and proportion in the sample are displayed, along with the resulting the margin of error and the confidence interval for the population proportion. Here is an example:

Confidence Interval - One population proportion: confidence level = 0.95
Input: Summary data

Number of trials Number of Events Sample proportion Margin of Error 95.00%CI
100 10 0.100 0.059 (0.0412, 0.1588)