A Z-test is a statistical tool used for determining the significance of the mean in a sample from a normally distributed population or between two independent samples.

Example of a Z-test

A sales clerk in a departmental store claims that 60% of the people entering the store leave without making a purchase. A random sample of 50 shoppers showed that 35 of them left without buying anything. With the help of a Z-test, we can now test whether the sample result is consistent with the claim of the sales clerk.

*Amreta Biswas: Senior Lecturer, Dept. of Business Administration, Central Women's University.