Share Z-test Z-test July 3, 2024376 views0 A statistical test used to determine whether two population means are different when the variances are known and the sample size is large. Share Lon BlytheCEO, Aside from being a white-hat hacker, Lon is a tech security analyst, cybersecurity professional, and a father of three. We’re not sure how he juggles all of that but the whole team agrees- he’s doing a fine job at it.