Chapter 5
1
Probability Densities
Continuous sample spaces and random variables
E.g. speed of a car, amount of alcohol in persons blood,
efficiency of solar collector, etc.
Example: If an accident occurs on a freeway of length 200 miles,
it will happen

Welcome to SEG2430
Spring 2010
Helen Meng
Professor
Department of Systems Engineering & Engineering
Management
1
Situation #1
Survey:
What is the fastest you have ever driven a car? _ mph
Received data from 87 males and 102 females
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14
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10
8
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2
0
Se

Chapter 3
1
Probability
Questions of interest:
What do we mean when we say that the probability of an event is
0.5, 0.02, 0.81?
How do we determine and measure the probabilistic values?
What are the mathematical rules that the probabilities must obey?

Caution
Mutually exclusive events do not imply independent
events
Be careful that P(AB)=P(A)P(B) applies only when A and
B are independent i.e. they are unrelated and there are
no common causes that jointly affect the occurrence of
both events
1
Chapter

Poisson Distribution
A frequently used model for counts without a natural
upper bound, Poisson distribution with mean
x e
f ( x; ) =
for x = 0,1,2,3. > 0
x!
If A1 , A2 , A3 ,.is a finite or infinite sequence of mutually exclusive
events in S, then
P(A1