Distributions Flashcards
type of poisson
discrete
PMF of poisson
Pr(X=k) = (lambda^k*e^-lambda)/k!
expectaion of poisson
E[X] = lambda
variance of poisson
Var(X) = lambda
exponential type
cts
PDF of exponential
f(x;lambda) = lambdae^(-lambdax)
CDF of exponential
F(x;lambda) = 1 - e^(-lambda*x)
E[X] and Var(X) of expontential
E[X] = 1/lambda
Var(X) = 1/lambda^2
Geometric type
discrete
PMF of Geometric
Pr(X=k) = (1-p)^k-1 * p
CDF of Geometic
F(k;p) = 1-(1-p)^k
E[X] and Var(X) of geometric
E[X] = 1/p
Var(X) = (1-p)/p^2
Binomical type
Discrete
PMF of binomial
Pr(x=k) = (n k)p^k(1-p)^n-k
E[X] and Var(X) of Binomail
E[X] = np
Var(X) = np(1-p)
uniform type
cts
PDF of unifrom
f(x;a,b) = 1/b-a
CDF of Uniform
F(x;a,b) = (x-a)/(b-a)
E[X] and var(X) of unifrom
E[X] = (a+b)/2
Var(X) = (b-a)^2/12