document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1158684>Question 1158684</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 11. What is the probability that a student scored less than 78?\r<BR>\n" );
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document.write( "P(x < 78) = \r<BR>\n" );
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document.write( "Express the probability as a decimal rounded to 4 decimal places. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #781675 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=781675\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "=(78-80)/11<BR>\n" );
document.write( "probability z<-2/11 is 0.4279<BR>\n" );
document.write( "We usually use z in the decimal form so here z=-0.182, but on a calculator one can use the fraction just as well.\r<BR>\n" );
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document.write( "2VARS 2 Normalcdf -6, -(2/11) .  Note, I use -6 rather than 1E99 just for simplicity since 6 sd s from the mean will not change the result to four decimal places. </SPAN>\n" );
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