A z-test is statistical test used to determine whether two population means are different when the variances are known and the sample size is large. What Is a Z-Test? A z-test is a statistical test ...

There are two common methods for statistical inference on 2 × 2 contingency tables. One is the widely taught Pearson chi-square test, which uses the well-known χ2 statistic. The chi-square test is ...