Sajun.org
In
mathematics, a
random variable is '''discrete''' if its
probability distribution is discrete; a '''discrete probability distribution''' is one that is fully characterized by a
probability mass function. Thus ''X'' is a discrete random variable if
:<math>\sum_u P(X=u) = 1</math>
as ''u'' runs through the set of all possible values of the random variable ''X''.
The
Poisson distribution, the
Bernoulli distribution, the
binomial distribution, the
geometric distribution, and the
negative binomial distribution are among the most well-known discrete probability distributions.
If a random variable is discrete then the
set of all possible values that it can assume is
finite or
countably infinite, because the sum of uncountably many positive
real numbers (which is the smallest upper bound of the set of all finite partial sums) always diverges to infinity.
nl:discrete stochastische variabele
