Apps. and Interpretation for IBDP Maths Ebook 1 | Page 274

Your Practice Set – Applications and Interpretation for IBDP Mathematics
Chapter
19
Discrete Probability
Distributions
SUMMARY POINTs
� Properties of a discrete random variable X :
X x
1
x
2 … x
n
P( X x)
P( X )
� � x1
x2
P( X � ) … P( X � x n
)
P( X � x ) � P( X � x ) � � P( X � x n
) � 1
1.
1 2
E( X ) � x P( X � x ) � x P( X � x ) � � x P( X � x ): Expected value of X
2.
1 1 2 2
3. E( X ) � 0 if a fair game is considered
n
n
Solutions of Chapter 19
264
SE Production Limited