In general, the probability distribution of a random variable X is defined as follows:
Definition 5 The probability distribution of a random variable X is the system of numbers
X
:
x1
x2 xn
P(X)
:
p 1
p 2 p n
where,
1
0,
n
i
i
i
p
p
 
 
 = 1, i = 1, 2, , n
The real numbers x1, x2,