document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1158686>Question 1158686</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A class is given an exam. The distribution of the scores is normal. The mean score is 80 and the standard deviation is 7. Determine the test score, c, such that the probability of a student having a score less than c is 90 %.\r<BR>\n" );
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document.write( "P(x < c) = 0.9\r<BR>\n" );
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document.write( "Find c rounded to one decimal place. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #781681 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=781681\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "when z=1.645, have the 90th percentile score<BR>\n" );
document.write( "1.645*7=x-mean<BR>\n" );
document.write( "11.5=x-mean<BR>\n" );
document.write( "x=91.5<BR>\n" );
document.write( "Below that score will be 90% of the scores or P(x<90.5)=0.9 </SPAN>\n" );
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