document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1110538>Question 1110538</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A researcher was recording the amount ,(in centimeters), the root system for a new variety of plant was growing during a 6 week period. A sample of 10 plants had the following lengths:\r<BR>\n" );
document.write( "\n" );
document.write( "2 . 5, 3, 2 . 7, 1.5, 2, 3.2, 4, 4.3, 1.7, 4.1\r<BR>\n" );
document.write( "\n" );
document.write( "What is the length that corresponds to the 25th percentile?<BR>\n" );
document.write( "                <BR>\n" );
document.write( "a. 1.7<BR>\n" );
document.write( "                <BR>\n" );
document.write( "b. 2<BR>\n" );
document.write( "                <BR>\n" );
document.write( "c. 3.2<BR>\n" );
document.write( "                <BR>\n" );
document.write( "d. 4.3 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #725751 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=725751\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=\"black\" face=\"times\" size=\"3\"><BR>\n" );
document.write( "The answer is choice B) 2\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "-----------------------------------------------------------------<BR>\n" );
document.write( "-----------------------------------------------------------------\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Explanation:\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Given Data Set = {2.5, 3, 2.7, 1.5, 2, 3.2, 4, 4.3, 1.7, 4.1}<BR>\n" );
document.write( "Sorted Data Set = {1.5, 1.7, 2, 2.5, 2.7, 3, 3.2, 4, 4.1, 4.3}\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I'm going to mark the middle most values in <font color=red>red</font> of the sorted set<BR>\n" );
document.write( "{1.5, 1.7, 2, 2.5, <font color=red>2.7, 3</font>, 3.2, 4, 4.1, 4.3}<BR>\n" );
document.write( "The middle values happen to be two values as there are an even number of items in this set<BR>\n" );
document.write( "The median is the midpoint of 2.7 and 3. <BR>\n" );
document.write( "The median is 2.85. <BR>\n" );
document.write( "We find this by averaging 2.7 and 3. So add them up and divide by 2: (2.7+3)/2 = 5.7/2 = 2.85\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Now break the sorted list into two halves. The lower half looks like<BR>\n" );
document.write( "L = {1.5, 1.7, 2, 2.5, 2.7}<BR>\n" );
document.write( "and the upper half is <BR>\n" );
document.write( "U = {3, 3.2, 4, 4.1, 4.3}\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "The lower half of values L = {1.5, 1.7, 2, 2.5, 2.7} are all below the median 2.85\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Locate the median of list L. The middle most value here is 2. <BR>\n" );
document.write( "So the first quartile is 2. This is the value of the 25th percentile which coincides with the first quartile (Q1).<BR>\n" );
document.write( "</font> </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );