Plus Four Confidence Interval for Proportion

Use this calculator to compute the plus four confidence interval for population proportion.

Confidence Interval Calculator for proportion
Sample Size ($n$)
Number of successes ($k$)
Confidence Level ($1-\alpha$)
Estimate of proportion: ($\hat{p}$)
Standard Error of proportion: ($SE$)
Z-critical value: ($Z_{\alpha/2}$)
Margin of Error: ($E$)
Lower Confidence Limits:
Upper Confidence Limits:

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