When comparing the means of samples from two normally distributed populations, if the samples are independent and the population variances are known, the $z$ test can be used.

Question

Quizplus · Accepted Answer

When comparing means from two normally distributed populations where the samples are independent and the population variances are known, the $z$ test is appropriate because it relies on the standard normal distribution and known variances to calculate the probability of observing the sample means if the null hypothesis is true.

When Comparing the Means of Samples from Two Normally Distributed zzz

When Comparing the Means of Samples from Two Normally Distributed $z$