Statistics Symbols

Symbol
μ - population mean - mean of population values
σ²  -  variance - variance of population values
σ_X -  standard deviation - standard deviation value of random variable X

x or M - sample mean - average / arithmetic mean
s ² - sample variance - population samples variance estimator
s - sample standard deviation - population samples standard deviation estimator
z_x - standard score, z_x = (x-x) / s_x
X ~ -  distribution of X - distribution of random variable X,  X ~ N(0,3)
N(μ,σ²) -  normal distribution
gaussian distribution
X ~ N(0,3)
U(a,b) - uniform distribution - equal probability in range a,b; X ~ U(0,3)
exp(λ) - exponential distribution
f (x) = λe^-λx , x≥0
gamma(c, λ)
gamma distribution
f (x) = λ c x^c-1e^-λx / Γ(c), x≥0
χ ²(k)
chi-square distribution
f (x) = x^k/2-1e^-x/2 / ( 2^k/2 Γ(k/2) )
F (k₁, k₂)
F distribution
Bin(n,p)
binomial distribution
f (k) = _nC_k p^k(1-p)^n-k
Poisson(λ)
Poisson distribution
f (k) = λ^ke^-λ / k!
Geom(p)
geometric distribution
f (k) =  p(1-p) ^k
HG(N,K,n)
hyper-geometric distribution
Bern(p)
Bernoulli distribution