Analysis and Approaches for IBDP Maths Ebook 1 | Page 255

Front Page
Chapter
19
Discrete Probability
Distributions
19
SUMMARY POINTs
� Properties of a discrete random variable X :
X x
1
x
2 … x
n
P( X x)
� P( X � x1
) X x2
P( � ) … P( X � x n
)
1.
1 2
P( X � x ) � P( X � x ) � � P( X � x n
) � 1
2.
1 1 2 2
E( X ) � x P( X � x ) � x P( X � x ) � � x P( X � x ): Expected value of X
3. E( X ) � 0 if a fair game is considered
n
n
Solutions of Chapter 19
247
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