View the content: Discrete Random Variables: Mean or Expected Value and Standard Deviation
Name:  Discrete Random Variables: Mean or Expected Value and Standard Deviation 
ID:  m16828 
Language:  English (en) 
Summary:  
Subject:  Mathematics and Statistics 
Keywords:  average, discrete, elementary, expected, large, law, longterm, mean, numbers, probability, random, statistics, variable 
License:  Creative Commons Attribution License CCBY 3.0 


Authors:  Susan Dean (susanldean45@gmail.com), Barbara Illowsky, Ph.D. (illowskybarbara@deanza.edu) 
Copyright Holders:  Maxfield Foundation (cnx@cnx.org) 
Maintainers:  Susan Dean (susanldean45@gmail.com), Barbara Illowsky, Ph.D. (illowskybarbara@deanza.edu), Connexions (cnx@cnx.org) 


Latest version:  1.16 (history) 
First publication date:  May 16, 2008 3:48 pm 0500 
Last revision to module:  May 27, 2012 12:06 pm 0500 
PDF:  m16828_1.16.pdf  PDF file, for viewing content offline and printing. Learn more. 
XML:  m16828_1.16.cnxml  XML that defines the structure and contents of the module, minus any included media files. Can be reimported in the editing interface. Learn more. 
Version:  1.16 May 27, 2012 12:06 pm 0500 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: Updated notation. 


Version:  1.15 May 22, 2012 8:36 am 0500 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: Minor word changes. 


Version:  1.14 Mar 14, 2012 10:26 am 0500 by Susan Dean 
Changes:  Module: Discrete Random Variables: Mean or Expected Value and Standard Deviation:Added " A computer randomly selects five numbers from 0 to 9 with replacement" to the example about a game of chance. 


Version:  1.13 Aug 11, 2011 10:26 pm 0500 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: Updated glossary item "Mean." 


Version:  1.12 Feb 23, 2009 4:26 pm 0600 by Chuck Bearden 
Changes:  Changed U+02C9 macrons into U+00AF macrons. 


Version:  1.11 Feb 6, 2009 7:50 am 0600 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: Clarified how to calculate the standard deviation for a discrete probability distribution by cleaning up the language and by showing the calculation. 


Version:  1.10 Jan 25, 2009 6:16 pm 0600 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: Corrected some punctuation and changed P(x) to P(X=x) in the glossary. 


Version:  1.9 Jan 21, 2009 6:32 pm 0600 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: For the last sentence in the first paragraph, ended the sentence after the word "average" for clarity. 


Version:  1.8 Jan 21, 2009 3:07 pm 0600 by Susan Dean 
Changes:  Discrete Random Variables: Mean or Expected Value and Standard Deviation: In the glossary, changed P(x) = P(X=x) since P(x) is the notation for probability function. Also, changed X with a bar over it to lower case x with a bar over it. 


Version:  1.7 Oct 27, 2008 2:09 pm 0500 by James Cooper 
Changes:  roles updated 


Version:  1.6 Jul 16, 2008 2:06 pm 0500 by Connexions 
Changes:  fixed math error and metadata 


Version:  1.5 Jul 9, 2008 4:08 am 0500 by Connexions 
Changes:  Post review edits 


Version:  1.4 Jul 8, 2008 5:55 pm 0500 by Connexions 
Changes:  post review edits 


Version:  1.3 Jul 7, 2008 12:32 pm 0500 by Connexions 
Changes:  post review updates 


Version:  1.2 Jun 27, 2008 11:27 am 0500 by Connexions 
Changes:  Roles changed 


Version:  1.1 Jun 23, 2008 12:53 am 0500 by Jonathan Emmons 
Changes:  Initial publication 
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Dean, S.; Illowsky, B. Discrete Random Variables: Mean or Expected Value and Standard Deviation, OpenStaxCNX Web site. http://cnx.org/content/m16828/1.16/, May 27, 2012.
Dean S, Illowsky B. Discrete Random Variables: Mean or Expected Value and Standard Deviation [OpenStaxCNX Web site]. May 27, 2012. Available at: http://cnx.org/content/m16828/1.16/.
Dean, S., & Illowsky, B. (2012, May 27). Discrete Random Variables: Mean or Expected Value and Standard Deviation. Retrieved from the OpenStaxCNX Web site: http://cnx.org/content/m16828/1.16/
Dean, Susan, and Barbara Illowsky. "Discrete Random Variables: Mean or Expected Value and Standard Deviation." OpenStaxCNX. May 27, 2012. http://cnx.org/content/m16828/1.16/.
Susan Dean and Barbara Illowsky, "Discrete Random Variables: Mean or Expected Value and Standard Deviation," OpenStaxCNX, May 27, 2012, http://cnx.org/content/m16828/1.16/.
Dean, S., & Illowsky, B. 2012. Discrete Random Variables: Mean or Expected Value and Standard Deviation. OpenStaxCNX, May 27, 2012. http://cnx.org/content/m16828/1.16/.
Dean, Susan, and Barbara Illowsky. Discrete Random Variables: Mean or Expected Value and Standard Deviation. OpenStaxCNX. 27 May 2012 <http://cnx.org/content/m16828/1.16/>.