document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1138409>Question 1138409</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Using diaries for many weeks, a study on the lifestyles of visually impaired students was conducted. The students kept track of many lifestyle variables including how many hours of sleep obtained on a typical day. Researchers found that visually impaired students averaged 9.25 hours of sleep, with a standard deviation of 2.51 hours. Assume that the number of hours of sleep for these visually impaired students is normally distributed.\r<BR>\n" );
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document.write( "Thirty percent of students get less than how many hours of sleep on a typical day?\r<BR>\n" );
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document.write( "answer: <BR>\n" );
document.write( " hours </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #756245 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=756245\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z  for 0.3000=-0.525<BR>\n" );
document.write( "z=(x-mean)/sd<BR>\n" );
document.write( "=(x-9.25)/2.51<BR>\n" );
document.write( "so -1.32=x-9.25<BR>\n" );
document.write( "x=7.93 hours </SPAN>\n" );
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