document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1167974>Question 1167974</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A survey of college students was conducted during final exam week to assess the number of hours spent studying each day. The mean number of hours was 5 with a standard deviation of 1.5 hours. The distribution was normal.\r<BR>\n" );
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document.write( "1.What percentage of students studied 7 or more hours per day?\r<BR>\n" );
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document.write( "2.What percentage of students studied 2 or more hours per day?\r<BR>\n" );
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document.write( "3.What percentage of students studied between 2 and 7 hours per day? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #851782 by </B><A HREF=/tutors/aboutme.mpl?userid=amarjeeth123><B>amarjeeth123(570)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=amarjeeth123><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=851782\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a standard normal distribution or Gaussian curve.\r<BR>\n" );
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document.write( "mu=5 hours<BR>\n" );
document.write( "sigma=1.5 hours\r<BR>\n" );
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document.write( "z=(x-mu)/sigma<BR>\n" );
document.write( "z1=(7-5)/1.5=2/1.5=4/3=1.3333 <BR>\n" );
document.write( "This can be done in Excel.<BR>\n" );
document.write( "P(x>7hours)=1-P(x<=7hours)=1-0.90878878=0.0913(approx)\r<BR>\n" );
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document.write( "The other two bits can be solved the same formula.\r<BR>\n" );
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document.write( "Hence proved. </SPAN>\n" );
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