document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1030508>Question 1030508</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An organization is trying to determine the mean IQ of professional pilots. How large a sample is required if they want to be 98% confident that the sample mean is within 4 IQ pts. of the population mean. Suppose you can assume that the standard deviation of pilot IQs is the same as the standard deviation of IQs for all adults, which is 15. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #645375 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=645375\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An organization is trying to determine the mean IQ of professional pilots. How large a sample is required if they want to be 98% confident that the sample mean is within 4 IQ pts. of the population mean. Suppose you can assume that the standard deviation of pilot IQs is the same as the standard deviation of IQs for all adults, which is 15. <BR>\n" );
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document.write( "Since E = z*s/sqrt(n),<BR>\n" );
document.write( "n = [zs/E]<BR>\n" );
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document.write( "n = [2.3263*15/4]^2 = 76 when rounded down<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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