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Summarise categorical or continuous data

2-sample z-test to compare sample proportion

  Sample 1 Sample 2
Sample proportion

Sample size


Compare two sample proportions using the 2-sample z-test. P-values can be calculated for one or two-tailed comparisons and are compared results to a specified significance level.

Inputs are:
  • sample proportions for each sample;
  • sample sizes for each sample;
  • specified significance level; and
  • whether test is one-tailed or two-tailed.

Outputs include:
  • difference in sample proportions;
  • Asymptotic (normal approximation) confidence limits (based on specified significance level) for the proportions and their difference;
  • z and P values for the difference in proportions and their interpretation;
  • whether or not z * p values are > 5 (to ensure test validity); and
  • a plot of the confidence limits.