document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=62946>Question 62946</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The following table shows data for the city K that consist of i ts population during the time period from the year 1942 to the year 2002.<BR>\n" );
document.write( "                         Scatter plotting<BR>\n" );
document.write( "1940- 20,360<BR>\n" );
document.write( "1950- 23,390<BR>\n" );
document.write( "1960- 28,580<BR>\n" );
document.write( "1970- 35,425<BR>\n" );
document.write( "1980- 45,260<BR>\n" );
document.write( "1990- 54,320<BR>\n" );
document.write( "2000- 63,525\r<BR>\n" );
document.write( "\n" );
document.write( "Find a qudratic model for the data.Round the values of a,b,and c to three significant digits? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #43780 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=43780\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Using the quadratic regression capability of a TI-83 I get<BR>\n" );
document.write( "y=6.691x^2+341.518x+1.000<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "Comment: Another way to do this problem would be to <BR>\n" );
document.write( "select 3 points, substitute their x-y values into <BR>\n" );
document.write( "y=ax^2+bx+c, thus generating three equations with <BR>\n" );
document.write( "three (a,b,c) unknows: then solving the system for <BR>\n" );
document.write( "a, b, and c. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );