The image above represents standard normal variable.

To compute for standard normal variable, three essential parameters are needed and these parameters are **value (x), mean (μ) **and **standard deviation (σ).**

The formula for calculating standard normal variable:

z = ^{(x – μ)} ⁄ _{σ}

Where;

z = Standard Normal Variable

x = Value

μ = Mean

σ = Standard Deviation

Let’s solve an example;

Find the standard normal variable when the value is 4, the mean is 20 and the standard deviation is 26.

This implies that;

x = Value = 4

μ = Mean = 20

σ = Standard Deviation = 26

z = ^{(x – μ)} ⁄ _{σ}

z = ^{(4 – 20)} ⁄ _{26}

z = ^{(-16)} ⁄ _{26}

z = -0.615

Therefore, the **standard normal variable** is **-0.615.**