document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1043314>Question 1043314</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An analysis of the final test scores for a selection test revealed that they approximate a normal distribution with a mean of 70 and a standard deviation 10.The examiner wants to award the grade “A” to upper 10%of the candidates and fail of the candidates who score the last 10% of the marks\r<BR>\n" );
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document.write( "(i) What is the minimum mark to obtain an “A” grade?<BR>\n" );
document.write( "(ii) What is the minimum mark a candidate to obtain in order to get pass marks?.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #658523 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=658523\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The z-value for the 90th percentile is 1.28<BR>\n" );
document.write( "z=(x-mu)/sd)<BR>\n" );
document.write( "1.28=(x-mu)/sd<BR>\n" );
document.write( "12.8=x-mu, since sd is 10 and we multiply both sides by 10.<BR>\n" );
document.write( "x=mu+12.8=82.8<BR>\n" );
document.write( "It is the opposite for the bottom 10%, where the z=-1.28<BR>\n" );
document.write( "x-mu=-12.8<BR>\n" );
document.write( "x-mu-12.8=57.2<BR>\n" );
document.write( "The minimum mark to get an A is 92.8 if tenths are allowed.<BR>\n" );
document.write( "The minimum mark to pass is 57.2<BR>\n" );
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