document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1119795>Question 1119795</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.9 grams per mile and standard deviation 0.2 grams per mile .\r<BR>\n" );
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document.write( "What sample size is needed so that the standard deviation of the sampling distribution is 0.01 grams per mile ? <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #735409 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=735409\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> population mean is 0.9 grams and population standard deviation is 0.2 grams<BR>\n" );
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document.write( "sample standard deviation is 0.01 grams<BR>\n" );
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document.write( "pick a confidence level of 90%, for a confidence level of 90%, the critical value is 1.645<BR>\n" );
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document.write( "acceptable error is 0.01/0.2 = 0.05<BR>\n" );
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document.write( "sample size = ((1.645 * 0.05) / 0.01)^2 = 43.2964 <BR>\n" );
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document.write( "since we have a residual we round the sample size up to 44<BR>\n" );
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