Statistics and probability
Z-score
The signed number of standard deviations a value lies from a distribution's mean.
Common notation z=(x−μ)/σ
In one sentence
What does Z-score mean?
The signed number of standard deviations a value lies from a distribution's mean.
How it is written
z=(x−μ)/σ
A compact example
If x=70, μ=50 and σ=10, then z=2.
Other names and search terms
standard score.
Clear answers
Questions about Z-score
What does Z-score mean in mathematics?
The signed number of standard deviations a value lies from a distribution's mean.
How is Z-score written?
A common notation is z=(x−μ)/σ.
What is an example of Z-score?
If x=70, μ=50 and σ=10, then z=2.