document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1161497>Question 1161497</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a.  The average IQ is 100, with a population standard deviation of 15. The mayor of Smartsville claims that citizens in his town have higher than average IQs. To test that claim, 40 Smartsville citizens were randomly selected, and their average IQ was determined to be 104.1. Does this support the mayor’s claim? Use α = 0.1.\r<BR>\n" );
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document.write( "b. construct a 90 % confidence interval for the mean.  Does the confidence interval support the claim made in part a?<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 #785076 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=785076\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a z-test with the usual assumptions<BR>\n" );
document.write( "z=(x bar-mean)/sigma/sqrt (n)<BR>\n" );
document.write( "Critical value is |z|>1.645<BR>\n" );
document.write( "z=(104.1-100)*sqrt(40)/15<BR>\n" );
document.write( "=1.73<BR>\n" );
document.write( "reject Ho and the average IQ is not 100 in Smartsville, it is higher, p-value is 0.084\r<BR>\n" );
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document.write( "90% CI half-interval is z*sigma/sqrt(40)  with z=1.645 <BR>\n" );
document.write( "half-interval is 3.90<BR>\n" );
document.write( "add and subtract from/to mean<BR>\n" );
document.write( "90% Confidence interval is (100.2, 108), and because 100 is not in the interval, is consistent with rejection of Ho in a.  \r<BR>\n" );
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