document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=361608>Question 361608</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The final exam scores of students taking a biology course at a university are normally distributed with a population mean of 73 and population standard deviation of 15. Nine students are randomly selected from the university and let x be their average score.<BR>\n" );
document.write( "What is the probability that their average biology score x is between 60 and 80?\r<BR>\n" );
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document.write( "Here's what I have so far...\r<BR>\n" );
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document.write( "z=(60-73)/5, z=(80-73)/5<BR>\n" );
document.write( "z=-2.6;1.4\r<BR>\n" );
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document.write( "P(-2.6 < x < 1.4)<BR>\n" );
document.write( "P(z<1.4)-P(z<-2.6) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #257782 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=257782\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The final exam scores of students taking a biology course at a university are normally distributed with a population mean of 73 and population standard deviation of 15. Nine students are randomly selected from the university and let x be their average score.<BR>\n" );
document.write( "What is the probability that their average biology score x is between 60 and 80? \r<BR>\n" );
document.write( "\n" );
document.write( "Here's what I have so far... <BR>\n" );
document.write( "z=(60-73)/5,e  z=(80-73)/5<BR>\n" );
document.write( "z=-2.6;1.4 <BR>\n" );
document.write( "P(-2.6 < x < 1.4)<BR>\n" );
document.write( "P(z<1.4)-P(z<-2.6)<BR>\n" );
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document.write( "You say the standard deviation is 15,<BR>\n" );
document.write( "but you use 5 as the standard deviation.<BR>\n" );
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document.write( "Assuming 5 is the correct number, you<BR>\n" );
document.write( "z-values are correct.<BR>\n" );
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document.write( "Your conclusion should be the following:<BR>\n" );
document.write( "P(60 < x < 80) = P(-2.6 < z < 1.4) = 0.9146<BR>\n" );
document.write( "==============================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "============= </SPAN>\n" );
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