� 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,
1,
1, 2, ,
n
i
i
i
p
p
i
n
=
>
=
=
∑
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 586
MATHEMATICS
� Let X be a random variable whose possible values x1, x2, x3,