probability for discrete random variablesnotes

Probability for - Probabilities Expected Values for Discrete Random Variables X is called a discrete random variable if the possible values of X

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Probabilities, Expected Values for Discrete Random Variables X is called a “discrete” random variable if the possible values of X consist only of a finite or countable number of possible values. Generally, this means that X is a variable that is arrived at by counting something. In this case, X is said to have a “probability mass function” (often denoted pmf) of the form p(x). This is just a shorthand way of writing P[X=x}, where x is one of the possible values of the random variable X. A function p(x) is a pmf if it satisfies the two requirements below (think of probabilities) …. . 1. p(x) is always greater than or equal to zero (and it is non-zero only for the possible values of the random variable X) 2. the total of the values of p(x) is one examples 1. p(1) =.3, p(2) = .5, p(3) = .2
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This note was uploaded on 02/01/2012 for the course STAT 490 taught by Professor Boyer during the Spring '11 term at Kansas State University.

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