document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=923323>Question 923323</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 12 hours, with a standard deviation of 3.5 hours. It is desired to estimate the mean viewing time within one-quarter hour. The 90 percent level of confidence is to be used.<BR>\n" );
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document.write( "How many executives should be surveyed? (Round up your answer to the next whole number.) <BR>\n" );
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document.write( "  Number of executives    \r<BR>\n" );
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document.write( "thanks a million! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #559979 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=559979\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  mean = 12 hours, with a standard deviation = 3.5 hours.<BR>\n" );
document.write( "estimate the mean viewing time within one-quarter hour. <BR>\n" );
document.write( "The 90 percent level of confidence is to be used.<BR>\n" );
document.write( "ME = .25 = 1.645(3.5/sqrt(n)<BR>\n" );
document.write( "n = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281.645%2A3.5%2F.25%29%5E2 ALIGN=MIDDLE  ALT=\"%281.645%2A3.5%2F.25%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 531 rounded Up to whole number </SPAN>\n" );
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