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. 
EPUB:  m16828_1.16.epub  Electronic publication file, for viewing in handheld devices. 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. 
Source Export ZIP:  m16828_1.16.zip  ZIP containing the module XML plus any included media files. Can be reimported in the editing interface. Learn more. 
Offline ZIP:  m16828_1.16_offline.zip  An offline HTML copy of the content. Also includes XML, included media files, and other support files. 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 
If you derive a copy of this content using a OpenStax_CNX account and publish your version, proper attribution of the original work will be automatically done for you.
If you reuse this work elsewhere, in order to comply with the attribution requirements of the license (CCBY 3.0), you must include
See the citation section below for examples you can copy.
The following citation styles comply with the attribution requirements for the license (CCBY 3.0) of this work:
Dean, S.; Illowsky, B. Discrete Random Variables: Mean or Expected Value and Standard Deviation, OpenStax_CNX 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 [OpenStax_CNX 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 OpenStax_CNX Web site: http://cnx.org/content/m16828/1.16/
Dean, Susan, and Barbara Illowsky. "Discrete Random Variables: Mean or Expected Value and Standard Deviation." OpenStax_CNX. 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," OpenStax_CNX, 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. OpenStax_CNX, 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. OpenStax_CNX. 27 May 2012 <http://cnx.org/content/m16828/1.16/>.