Confidence Interval Capture Simulator

Take repeated samples and watch whether each confidence interval captures the true population parameter. The long-term capture rate should approach the selected confidence level.

Parameter Type

Confidence Level 95%

Drag the slider to immediately redraw every interval. Higher confidence makes intervals wider.

Sample Size

True μ

True σ

For the mean mode, intervals use z* · σ/√n so the population standard deviation is known.

Intervals

Captured

Capture Rate

—

Captured parameter Missed parameter True parameter

Tip: Drag the confidence slider after stacking intervals. Higher confidence levels use a larger critical value, so each interval widens and the capture rate usually increases.