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Unformatted text preview: function:
pX (x ) = n
x 0 px q n−x if x = 0, 1, 2, . . . , n
where x = x !(n−x )! counts the number of ways of distributing x
successes among n trials, and n! = n × (n − 1) × . . . × 3 × 2 × 1
Statistics: µ = E (X ) = np
σ 2 = Var(X ) = npq
Math 30530 (Fall 2012) Discrete Random Variables October 7, 2012 3 / 10 The Geometric random variable
When to use: When you want to count how many times you have
to repeat the same experiment, independently of each other,
until you ﬁrst have success
p: the probability of success on each individual trial Mass function:
pX (x ) = q x −1 p i...
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This document was uploaded on 03/13/2014 for the course ECON 205 at American University of Beirut.
- Spring '11