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<document xmlns="http://cnx.rice.edu/cnxml" xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:bib="http://bibtexml.sf.net/" id="id4193428">
<name>What is an Independent Variable?</name>
<metadata>
  <md:version>1.1</md:version>
  <md:created>2006/02/21 10:30:39.467 US/Central</md:created>
  <md:revised>2006/02/22 06:58:03.860 US/Central</md:revised>
  <md:authorlist>
      <md:author id="kolobl">
      <md:firstname>Lekulana</md:firstname>
      <md:othername>Emmanuel</md:othername>
      <md:surname>Kolobe</md:surname>
      <md:email>klekulana@hotmail.com</md:email>
    </md:author>
  </md:authorlist>

  <md:maintainerlist>
    <md:maintainer id="kolobl">
      <md:firstname>Lekulana</md:firstname>
      <md:othername>Emmanuel</md:othername>
      <md:surname>Kolobe</md:surname>
      <md:email>klekulana@hotmail.com</md:email>
    </md:maintainer>
  </md:maintainerlist>
  
  <md:keywordlist>
    <md:keyword>Dependent Variable</md:keyword>
    <md:keyword>Independent Variable</md:keyword>
  </md:keywordlist>

  <md:abstract>This module introduces an independent variable, gives example of such variables and an exercise.</md:abstract>
</metadata>
<content>
<para id="id9919240">An <term>independent variable</term> is that variable which
is presumed to affect or determine a <link src="http://cnx.rice.edu/content/m13446/latest">dependent variable</link>. It can be
changed as required, and its values do not represent a problem
requiring explanation in an analysis, but are taken simply as
given [<link src="http://en.wikipedia.org/wiki/Independent_variable">Wikipedia2006I</link>].</para>
<para id="id4226339">More generally, the <term>independent variable</term> is the
thing that someone actively changes; while the <link src="http://cnx.rice.edu/content/m13446/latest">dependent variable</link>
is the thing that changes as a result.</para>
<example id="element-459"><para id="element-978">The wages of an employee depend on the time worked. Time is the independent variable that varies among employees, and the wages are calculated directly from the total time worked. Thus wages are dependent on time worked. [taken from <link src="http://en.wikipedia.org/wiki/Independent_variable">Wikipedia2006I</link>]
	</para>
<para id="element-979">
In a call centre, the number of customers serviced per hour, depends on the number of agents, and average service time per customer. In this case number of customers is a dependent variable, entirely dependent on the other two independent variables namely agents, and average service time. 
</para>
</example><exercise id="element-97"><problem>
		<para id="element-264">
			What is an independent variable in the following function? Briefly explain your choice.
		</para>
<para id="element-265">
Y = 3X + Z - 5 
</para>
</problem>

	<solution>
		<para id="element-433">There are two independent variables namely X, and Z. This is because their values can change  freely regardless of the value of X, and that change is going to affect X as a result.
		</para>
	</solution>
</exercise><para id="id30373186"><term>References:</term></para>
<list type="bulleted" id="id30353019"><item>Wikipedia2006I. "<emphasis>Independent Variable</emphasis>,"  
<link src="http://en.wikipedia.org/wiki/Regression_analysis">
http://en.wikipedia.org/wiki/Independent_variable</link>, Last
Accessed on 20 February 2006</item>
<item>Author of Assignment 3: Lekulana Kolobe</item>
<item>Author of Assignment 1: Arnold Mwesigye</item>
</list>
</content>
</document>
