September 2012
Intermediate to advanced
486 pages
10h 41m
English
1.4 Several random variables
1.4.1 Two discrete random variables
Suppose that with each elementary event ω in Ω, we can associate a pair of integers
. We write
![]()
Strictly speaking, p(m, n) should be written as
for reasons discussed earlier, but this degree of pedantry in the notation is rarely necessary. Clearly
![]()
The sequence (p(m, n)) is said to be a bivariate (probability) density (function) or bivariate pdf and is called the joint pdf
of the random variables m and n (strictly
and
). The corresponding joint distribution function, joint cdf or joint df is
![]()
Clearly, the density of m (called its marginal density) is
![]()
We can also define a conditional distribution for n given m (strictly for given ...