document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=286250>Question 286250</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In Florida, when there were 447 boats registered there were 13 manatees killed that year. During a year when there were 719 boats registered there were 47 manatees killed that year. Assuming a linear relationship between boats registered and manatees killed, find a linear equation that describes the number of manatees killed with respect to boats registered. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #207586 by </B><A HREF=/tutors/aboutme.mpl?userid=dabanfield><B>dabanfield(803)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=dabanfield><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=207586\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In Florida, when there were 447 boats registered there were 13 manatees killed that year. During a year when there were 719 boats registered there were 47 manatees killed that year. Assuming a linear relationship between boats registered and manatees killed, find a linear equation that describes the number of manatees killed with respect to boats registered.\r<BR>\n" );
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document.write( "The two points (447,13) and (719,47) are on the line.\r<BR>\n" );
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document.write( "The slope of the line is (47-13)/(719-447) = 34/272 = 1/7.\r<BR>\n" );
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document.write( "The equation of the line in slope-intercept form is:\r<BR>\n" );
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document.write( "y = m*x + b where m is the slope and b is the value of y where the line crosses the y-axis.\r<BR>\n" );
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document.write( "So far we have:\r<BR>\n" );
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document.write( "y = (1/7)*x + b\r<BR>\n" );
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document.write( "To find b we know we can use the fact that when x is 447 then y = 13. Substituting these values in the equation above we have:\r<BR>\n" );
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document.write( "13 = (1/7)*447 + b\r<BR>\n" );
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document.write( "13 = 447/7 + b\r<BR>\n" );
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document.write( "b = 13 - 447/7<BR>\n" );
document.write( "b = 13 - 63.18<BR>\n" );
document.write( "b = -50.18\r<BR>\n" );
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document.write( "We have then y = (1/7)*x - 50.18 \r<BR>\n" );
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document.write( "  </SPAN>\n" );
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