Difference between revisions of "Probability mass function"

From Conservapedia
Jump to navigation Jump to search
m
(→‎top: clean up & uniformity)
 
(3 intermediate revisions by 3 users not shown)
Line 1: Line 1:
−
In [[probability theory]], a ''probability mass function'' say ''p'' is a real valued function of a discrete variable say ''x'', such that the value ''p(x<sub>k</sub>)'' is the probability of the variable ''x'' having the value x<sub>k</sub>.   
+
In [[probability theory]], a '''probability mass function''' (''p(x)'') is a real-valued function of a discrete variable (''x''), such that the value ''p(x<sub>k</sub>)'' is the probability of the variable ''x'' having the value x<sub>k</sub>.   
  
 
In order to qualify, such a function must meet the following criteria:
 
In order to qualify, such a function must meet the following criteria:
  
−
<math>p(x_{k}) \geq 0 </math> <math> \forall x </math>
+
*<math>p(x_{k}) \geq 0; \forall x </math>
 +
*<math>\sum_{k} p(x_{k}) = 1  </math>
  
 +
The collection of pairs ( x<sub>k</sub> , p(x<sub>k</sub>) ) is the [[discrete]] [[probability distribution]] of ''x''.
  
−
<math>\sum_{k} p(x_{k}) = 1  </math>
+
[[Category:Probability and Statistics]]
−
 
 
−
 
 
−
The collection of pairs ( x<sub>k</sub> , p(x<sub>k</sub>) ) is the (discrete) [[probability distribution]] of ''x''.
 
−
 
 
−
[[Category:mathematics]]
 

Latest revision as of 17:52, July 13, 2016

In probability theory, a probability mass function (p(x)) is a real-valued function of a discrete variable (x), such that the value p(xk) is the probability of the variable x having the value xk.

In order to qualify, such a function must meet the following criteria:

  • <math>p(x_{k}) \geq 0; \forall x </math>
  • <math>\sum_{k} p(x_{k}) = 1 </math>

The collection of pairs ( xk , p(xk) ) is the discrete probability distribution of x.