document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=239045>Question 239045</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Okay, i kinda asked a question like this earlier but i forgot one thing. <BR>\n" );
document.write( "A chart shows ideal heights and weights for adults with a medium build. A person with the height of 6o inches should have a weight of 112 pounds and a person with the height of 66 inches should have a weight of 136. <BR>\n" );
document.write( "Write a linear equation to estimate the weight of a person of any height. <BR>\n" );
document.write( "HOW DO I DO THAT?<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 #175578 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=175578\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 60 inches = 112 pounds<BR>\n" );
document.write( "66 inches = 136 pounds\r<BR>\n" );
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document.write( "let x = inches and y = pounds\r<BR>\n" );
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document.write( "(x1,y1) = 60,112)<BR>\n" );
document.write( "(x2,y2) = 66,136)\r<BR>\n" );
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document.write( "slope of straight line = y2-y1/(x2-x1) = (136-112)/(66-60) = 24/6 = 4\r<BR>\n" );
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document.write( "slope-intercept form of straight line equation is y = mx+b where m is the slope and b is the y-intercept.\r<BR>\n" );
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document.write( "your equation is y = 4x + b because it has a slope of 4.\r<BR>\n" );
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document.write( "substitute either one of the points (x1,y1) or (x2,y2) in the equation to solve for the y-intercept which is b.\r<BR>\n" );
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document.write( "equation of y = 4x + b becomes:\r<BR>\n" );
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document.write( "112 = 4*60 + b if we use (x1,y1).\r<BR>\n" );
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document.write( "solving for b we get:\r<BR>\n" );
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document.write( "112 = 240 + b<BR>\n" );
document.write( "b = 112-240 = -128\r<BR>\n" );
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document.write( "equation becomes y = 4x - 128\r<BR>\n" );
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document.write( "graph of this equation looks like:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28600%2C600%2C-10%2C100%2C-10%2C200%2C4x-128%2C112%2C136%29 ALIGN=MIDDLE  ALT=\"graph%28600%2C600%2C-10%2C100%2C-10%2C200%2C4x-128%2C112%2C136%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "the graph has y = 112 and 136 to show you that they occur at x = 60 and x = 66 as they should.\r<BR>\n" );
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document.write( "lso not very accurate although not quite as bad as on the low end.\r<BR>\n" );
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document.write( "If you restricted the domain for the value of x being from 50 to 70 then the graph straight line project might be ok.\r<BR>\n" );
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document.write( "Since this graph is a straight line calculated between only 2 points, it doesn't accurately portray the height to weight ratio at the extremes of the height range.\r<BR>\n" );
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