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Next: Continuous random variables 9/30 Up: Basic Concepts Previous: Determination of probabilities 9/29

Infinite Sample Spaces 9/29

Example: Toss a coin until heads comes up.

\begin{displaymath}\Omega=\{1,2,3,\ldots \}\end{displaymath}

Looking at the tree diagram, we see that P(1)=1/2, P( 2 )=1/4, P(3)=1/8........

The distribution function in this case is: m(i)=1/2i

But we have to check that $\sum_\omega m(\omega)=1$

What is the probability that heads turns up after an even number of tosses?

Susan Holmes