document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=115837>Question 115837</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0072934824/algebrahomeworkh>Algebra For college students</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Hello I need some help.\r<BR>\n" );
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document.write( "As the number of farms has decreased in llinios, the average size of the remianing farms has grown larger,as shown below\r<BR>\n" );
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document.write( "Year  Average Acreage per farm <BR>\n" );
document.write( "1900    127<BR>\n" );
document.write( "1910    119<BR>\n" );
document.write( "1920    135<BR>\n" );
document.write( "1930    137<BR>\n" );
document.write( "1940    155<BR>\n" );
document.write( "1950    196<BR>\n" );
document.write( "1960    283<BR>\n" );
document.write( "1970    353<BR>\n" );
document.write( "1980    406<BR>\n" );
document.write( "1990    440<BR>\n" );
document.write( "2000    420\r<BR>\n" );
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document.write( "let x represent the number of years since 1900. Use a graphing calculator to fit a function to the data. Select the model which gives best fit. Write the equation , the coeffienct of determination, and estimate to nearest arce the average acreage in 2011. Use regression feature in calculator. This problem is  really hard can anyone help me thanks<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 #84309 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=84309\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Put the data in L1, L2<BR>\n" );
document.write( "Run the regressions against L1,L2<BR>\n" );
document.write( "Look for the result with the highest \"r\" value.<BR>\n" );
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document.write( "I find the QuartReg gives the highest r but gives a \"0\" <BR>\n" );
document.write( "coefficient of the x^4 term. So I switched to the CubicReg<BR>\n" );
document.write( "and got:<BR>\n" );
document.write( "f(x) = -0.001x^3 + 0.196x^2 - 5.298x + 143.552<BR>\n" );
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document.write( "coefficient of determination = ??<BR>\n" );
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document.write( "f(2011) is negative using the cubic but positive using the <BR>\n" );
document.write( "QuadReg which is f(x) = 0.025x^2+1.211x + 102.587<BR>\n" );
document.write( "and gives f(2011) = 103641 which doesn't sound very reasonable.\r<BR>\n" );
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document.write( "Good luck on this.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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