Statistics and probability
Z-score
The signed number of standard deviations a value lies from a distribution's mean.
Common notationz=(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.
Where this fits
When should you learn Z-score?
The first encounter is not the final level. Many ideas begin visually, become computational in high school and become formal in college.
- 1Pre-high schoolPrepare foundations
- 2High schoolUsually introduced
- 3CollegeGreater depth
- 4AdvancedGreater depth
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Quantum predictions are expressed through probabilities and expected values.
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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.