Z Score Calculator For 2 Population Proportions

Home » When To Use A Two Proportion Z Test » Z Score Calculator For 2 Population Proportions

Maybe your like

Social Science StatisticsHomeTestsPowerDescriptiveChartsTutorialsUtilitiesMenuHomeTestsPowerDescriptiveChartsTutorialsUtilitiesZ-Test Calculator for 2 Population Proportions

This calculator performs a Z-test to compare the proportions of two independent populations or groups.

Go to Calculator →

When to Use

Use the Z-test for proportions when you want to compare the proportion of successes in two independent groups (e.g., proportion of patients responding to treatment in two different drug groups).

Requirements

  • Two independent samples
  • Binary outcome (success/failure)
  • Sufficient sample size (typically np > 5 and n(1-p) > 5 for both groups)

Null Hypothesis

H₀: p₁ = p₂ (the two population proportions are equal)

Formula

Z = (p₁ - p₂) / SE

where SE = √[p̂(1-p̂)(1/n₁ + 1/n₂)]

and p̂ = (x₁ + x₂) / (n₁ + n₂)

Calculate Z-Test

Quick Links

  • T-Test Calculator
  • ANOVA Calculator
  • Chi-Square Test
  • Pearson Correlation

About

Free statistical calculators for students and researchers in the social sciences. No registration required.

Not sure which test?

Let our wizard help you choose the right statistical test.

Start Wizard →

Tag » When To Use A Two Proportion Z Test