document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=213459>Question 213459</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A random sample of 100 students at Southern University was collected. The mean age was found to be 24.2 years, with a standard deviation of 3.4 years.<BR>\n" );
document.write( "(a) What percentage of students are over 27.6 years old?  4%<BR>\n" );
document.write( "(b) What percentage of the students are between 20.8 and 24.2 years old?  9% <BR>\n" );
document.write( "(c) If a student is selected at random from Southern University, what is the probability that he or she will be over 20.8 years old? 5%\r<BR>\n" );
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document.write( "Ignore the 4 percent, 9 percent and the 5 percent that was what I think the answer is.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #161243 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=161243\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A random sample of 100 students at Southern University was collected. The mean age was found to be 24.2 years, with a standard deviation of 3.4 years.<BR>\n" );
document.write( "(a) What percentage of students are over 27.6 years old? <BR>\n" );
document.write( "Find the z-score of 27.6.<BR>\n" );
document.write( "z(27.6) = (27.6-24.2)/3.4 = 1<BR>\n" );
document.write( "Then P(x > 27.6) = P(z > 1) = 0.1587<BR>\n" );
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document.write( "(b) What percentage of the students are between 20.8 and 24.2 y0.34ears old? <BR>\n" );
document.write( "Find the z-scores of the two numbers:<BR>\n" );
document.write( "z(24.2) = 0<BR>\n" );
document.write( "z(20.8) = (20.8-24.2) = -3.4=2.4 = -1<BR>\n" );
document.write( "P(20.8 < x < 24.2) = P(-1 < z < 0) = 0.3413<BR>\n" );
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document.write( "(c) If a student is selected at random from Southern University, what is the probability that he or she will be over 20.8 years old? <BR>\n" );
document.write( "z(20.8 = -1<BR>\n" );
document.write( "P(x > 20.8) = P(z > -1) = 0.8413<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "stan H. <BR>\n" );
document.write( " </SPAN>\n" );
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