The document describes how to calculate a single-sample z-test. It explains that the z-critical value is determined by the significance level, often 0.05 corresponding to z-values of -1.96 and 1.96. An example calculates the z-statistic to test if sample data matches a population claim. It finds the z-statistic is -2.67, which is outside the critical values and considered rare, so the null hypothesis that the sample matches the claim is rejected.