document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1157930>Question 1157930</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The marks on statisties midierm test are normally distobuted witha mean of 78 and a slandard deviation of 6. (a) What proportion of the elass has a midierm ntark ot less than 75? (B) What is the probabilily that class of 50 has an average midterm mark that is less than 75? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #780860 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=780860\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "for a z <-1/2 and that probability is 0.3085\r<BR>\n" );
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document.write( "z=(x bar-mean)/sigma/sqrt(n)<BR>\n" );
document.write( "here, z< (-3)*sqrt(50)/6 or -3.54 and that probability is 0.0002\r<BR>\n" );
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document.write( "Far less likely for the whole class to get below 75. </SPAN>\n" );
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