Basic Statistical Symbols


C 
A
distribution, also called the distribution for the independent variable 

U 
A
distribution that is that the not same as X, also called the dependent
variable 

SC 
Sum
all the elements [numbers] in the distribution 

SC^{2} 
Square
all the elements [numbers] then add them to each other 

(SC)^{2} 
Add
all the elements then square the summation 

N 
The
number of elements in a population distribution 

n 
The
number of elements in a sample distribution 

X_{1} 
The
first element [number] in a distribution 

X_{2} 
The
second element [number] in a distribution 

X_{n} 
The
last element in a distribution 

… 
All
the elements between two points in a distribution 

SCY 
Multiply
X_{1} by Y_{1}, X_{2} by Y_{2}, …, X_{n} by Y_{n}and
sum the distribution 

a 
Greek
letter for alpha: the intercept or a type I error 

b 
Greek
letter for beta: the slope or a type II error 

s 
Greek
letter for sigma, meaning the standard deviation for the population 

s 
Letter
s, meaning the standard deviation for the sample 

s^{2} 
Letter s square, meaing the variance for the sample  
s_{1}  In a time series, the first data point; subscripts note the location of the data point  
s_{n – 1}  In a time series, the second to the last data point.  
s_{n }  In a time series, the last data point.  
m 
Greek
letter mu, meaning the [arithmetic] mean of the population 

Also call "Xbar" meaning the [arithmetic] mean of the sample  
Md 
Median 

Mo 
Mode 

Gm 
Geometric
mean 

Hm 
Harmonic
mean 
[*] Population
vs Sample
The population includes all objects of interest whereas the sample is only
a portion of the population. Parameters are associated with populations and
statistics with samples. Parameters are usually denoted using Greek letters
while statistics are usually denoted using Roman letters.