The Mathematical Symbols used in Statistics
wayne.smith@csun.edu
[ updated: Saturday, April 19, 2008 ]
“All wisdom is rooted in learning to call things by the right name.”
---Confucious (c. 500 B.C.)
Purpose:
The purpose of this document is clearly identify the many mathematical symbols used in
typical statistics problems. Mathematics is the language of science. Statistics is the
language of research. Students need to master these symbols because these symbols are
the standard nomenclature in statistical reasoning.
In general, Greek letters are used for measures of the population (called “parameters”)
and Latin letters are used for measures of one or more samples (called “statistics”). The
pronunciation and vernacular for each symbol is included as well.
Symbol
Concept
Number of
Observations (size)
Mean
Variance
Standard Deviation
Proportion
Correlation
Coefficient
Population
N (big “en”)
Sample
n (little “en”)
μ (“mu”)
σ (lower case “sigma” squared)
σ (lower case “sigma”)
π (lower case “pi”)
ρ (lower case “rho”)
x (“x-bar”)
s (“ess-squared”)
s (“ess”)
p (little “pea”)
r (little “are”)
2
2
Other Greek and Latin letters are used to symbolize various numerical quantities and
mathematical transformations.
Concept
Summation
Sum Product
Type I Error
Type II Error
Regression – y-intercept (constant)
Regression – slope
Regression – actual y value
Regression – predicated y value
Square of the correlation
(multiple) Coefficient of Determination
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Symbol
∑ (upper case “sigma”)
Π (upper case “pi”)
α (lower case “alpha”)
β (lower case “beta”)
b0
b1
y (“why”)
ŷ (“why hat”)
r2 (little “are squared”)
R2 (big “are squared”)