document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=540746>Question 540746</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boy who is 4 feet 6 inches tall casts a shadow that is 6 feet 3 inches long. What is the height of a tree that casts a shadow that is 25 feet long?\r<BR>\n" );
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document.write( "I know that it is direct variation and that I need to use the equation y=kx. In my instruction, however, there were only example problems in which x was changed. I may be completely off base but I assumed that I could do the equation as followed:\r<BR>\n" );
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document.write( "y(height of boy)=4.6; x(shadow)=6.25<BR>\n" );
document.write( "solve for y=6.25<BR>\n" );
document.write( "y(k)=x<BR>\n" );
document.write( "k(25)=6.25 <BR>\n" );
document.write( "k(25)/6.25 = 6.25/6.25<BR>\n" );
document.write( "k=4\r<BR>\n" );
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document.write( "4.6 (4) = x<BR>\n" );
document.write( "x=18.4\r<BR>\n" );
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document.write( "18 is an answer... but that doesn't seem right.\r<BR>\n" );
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document.write( "And then I realized that something terribly wrong happened. Thank you so much to who ever might decide to help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #353863 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=353863\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x and y represent an object and its shadow<BR>\n" );
document.write( "___ it makes no difference which letter represents which parameter, as long as you are consistent<BR>\n" );
document.write( "___ yes, this is a direct variation; bigger objects have bigger shadows\r<BR>\n" );
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document.write( "let x be the object and y the shadow<BR>\n" );
document.write( "___ work in consistent units ___ feet, in this case\r<BR>\n" );
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document.write( "6.25 = k * 4.5 ___ k = 6.25 / 4.5\r<BR>\n" );
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document.write( "25 = k * x ___ 25 / k = x ___ 25 / (6.25 / 4.5) = x ___ 18 = x\r<BR>\n" );
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document.write( "you did find the right answer, but your technique needs work (you were lucky...) </SPAN>\n" );
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