document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1071056>Question 1071056</A>: <I><SPAN STYLE=\"word-break: break-all;\"> According to Nielsen Media Research, the (population) average number of hours of TV viewing per household per week in the United States is 50.4 hours. Suppose the (population) standard deviation is known to be 11.8 hours.  A random sample of 42 U.S. households is taken.  (Hint:  Review the central limit theorem about sampling distributions)\r<BR>\n" );
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document.write( "a.	What is the probability that the sample mean is more than 52 hours?\r<BR>\n" );
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document.write( "b.	What is the probability that the sample mean is less than 47.5 hours?\r<BR>\n" );
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document.write( "c.	What is the probability that the sample mean is less than 40 hours?\r<BR>\n" );
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document.write( "d.	Assume that the sample mean actually is less than 40 hours.  What does this mean about the Nielsen Media Research figures that claim the population mean is 50.4 hours?  Explain.<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 #686235 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=686235\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sigma/sqrt(n)<BR>\n" );
document.write( "> (52-50.4)/11.8/sqrt(42)=1.6/1.82=0.1898<BR>\n" );
document.write( "probability is 0.1898<BR>\n" );
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document.write( "< (47.5-50.4)/11.8/sqrt(42)=less than -2.9/1.821 or < z of -1.592<BR>\n" );
document.write( "Probability is 0.0557<BR>\n" );
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document.write( "<-10.4/1.821 or z< -5.711<BR>\n" );
document.write( "This is <<0.0001<BR>\n" );
document.write( "If that is the case, then the claim is not likely to be true. </SPAN>\n" );
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