document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=888795>Question 888795</A>: <I><SPAN STYLE=\"word-break: break-all;\"> blood pressure readings are approximately normal with a mean of 120 and a standard deviation of 8. A researcher wishes to select people for a study but wants to exclude the top & bottom 10%. What would be the upper and lower reading to qualify people to participate in the study? Please help I've spent almost an hour on this question </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #537706 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=537706\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> blood pressure readings are approximately normal with a mean of 120 and a standard deviation of 8. A researcher wishes to select people for a study but wants to exclude the top & bottom 10%. What would be the upper and lower reading to qualify people to participate in the study? <BR>\n" );
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document.write( "Find the z-value with a right tail of 10%::<BR>\n" );
document.write( "invNorm(0.9) = 1.2816<BR>\n" );
document.write( "Find the z-value with a left tail of 10%::<BR>\n" );
document.write( "invNorm(0.1) = -1.2816<BR>\n" );
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document.write( "Lower limit:: x = -1.2816*8+120 = 129.16<BR>\n" );
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document.write( "Upper limit:: x = +1.2816*8+120 =  130.25<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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