document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1056949>Question 1056949</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Confidence Interval (Please be as Detailed as Possible)\r<BR>\n" );
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document.write( " The lengths (in inches) of 9 fish caught in Falcon Lake are given below:\r<BR>\n" );
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document.write( "       8.8, 33.7,   3.1,   5.1,   28.0,   13.5,   9.5,   12.1,   7.7\r<BR>\n" );
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document.write( "Assume that the distribution of lengths of fish in this lake is normal\r<BR>\n" );
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document.write( "a. Estimate the true mean length of the fish in this lake with 80% confidence.\r<BR>\n" );
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document.write( "              (Hint: the standard deviation of the 9 fish caught is 10.4 inches.)\r<BR>\n" );
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document.write( "b. Write a brief summary interpreting your answer to part (a). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #672036 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=672036\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The mean is 13.5, the sd is 10.4<BR>\n" );
document.write( "the interval is t(0.90, df=8)*10.4/sqrt (9)=1.397*10.4/3=4.84<BR>\n" );
document.write( "The 80% CI is the mean +/- 4.84 or (5.56,15.24) units inches<BR>\n" );
document.write( "That means we are 80% confident that the true value is in the interval.  We don't know the true value and never will, but we are moderately confident it is between 5.56 and 15.24 inches.<BR>\n" );
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