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 ...

The z test is a commonly used hypothesis test in inferential statistics that allows us to compare two populations using the mean values of samples from those populations, or to compare the mean of one ...

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 ...