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 ...

A two-sample z-test for population means compares two population means. It is appropriate when the population standard deviations are known and the sample sizes are large. This web calculator conducts ...

This applet allows users to specify a hypothesized population proportion, sample proportion and sample size as well as an alternative hypothesis and significance level. After changing the values, the ...