document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=140638>Question 140638</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 2.	Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are $2,500 for setup costs and $3.00 to administer each test. \r<BR>\n" );
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document.write( "a.	Write an expression that gives the total cost to test x animals.\r<BR>\n" );
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document.write( "b.	You can find the average cost per animal by dividing total costs by number of animals. Write the expression that gives the average cost per animal.\r<BR>\n" );
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document.write( "c.	Find the average cost per animal for 10 animals. 100 animals. 1,000 animals.\r<BR>\n" );
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document.write( "d.	As the number of animals tested increases, what happens to the average cost to test the animals? Would the average cost ever fall below $3.00? If so, identify a value that supports your answer. If not, explain how you know. \r<BR>\n" );
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document.write( "e.	How many animals should be tested for the average cost to be $5.00 per animal? <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 #102353 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=102353\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a)\r<BR>\n" );
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document.write( "In this case, the startup cost ($2,500 ) is the fixed cost and the cost to administer each test ($3.00 ) is the variable cost\r<BR>\n" );
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document.write( "Also, remember the cost function in general is \r<BR>\n" );
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document.write( "Cost = variable cost*x + fixed cost\r<BR>\n" );
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document.write( "So in our case, the cost function is \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=C=3x%2B2500 ALIGN=MIDDLE  ALT=\"C=3x%2B2500\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "b)\r<BR>\n" );
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document.write( "To find the average cost, simply take the total cost (which is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3x%2B2500 ALIGN=MIDDLE  ALT=\"3x%2B2500\"   DISABLED_style= \"max-width:90%; height:auto;\" >) and divide it by x like this\r<BR>\n" );
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document.write( "Average Cost:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283x%2B2500%29%2Fx ALIGN=MIDDLE  ALT=\"A=%283x%2B2500%29%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "c)\r<BR>\n" );
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document.write( "Average cost for 10 animals\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283%2810%29%2B2500%29%2F%2810%29=%2830%2B2500%29%2F%2810%29=%282530%29%2F%2810%29=253 ALIGN=MIDDLE  ALT=\"A=%283%2810%29%2B2500%29%2F%2810%29=%2830%2B2500%29%2F%2810%29=%282530%29%2F%2810%29=253\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the average cost per animal is $253\r<BR>\n" );
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document.write( "Average cost for 100 animals\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283%28100%29%2B2500%29%2F%28100%29=%28300%2B2500%29%2F%28100%29=%282800%29%2F%28100%29=28 ALIGN=MIDDLE  ALT=\"A=%283%28100%29%2B2500%29%2F%28100%29=%28300%2B2500%29%2F%28100%29=%282800%29%2F%28100%29=28\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the average cost per animal is $28\r<BR>\n" );
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document.write( "Average cost for 1,000 animals\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283%281000%29%2B2500%29%2F%281000%29=%283000%2B2500%29%2F%281000%29=%285500%29%2F%281000%29=3.5 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the average cost per animal is $5.50\r<BR>\n" );
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document.write( "d)\r<BR>\n" );
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document.write( "As the number of animals tested increases, the average cost per animal decreases.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283x%2B2500%29%2Fx ALIGN=MIDDLE  ALT=\"A=%283x%2B2500%29%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the average cost function\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3=%283x%2B2500%29%2Fx ALIGN=MIDDLE  ALT=\"3=%283x%2B2500%29%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=3 ALIGN=MIDDLE  ALT=\"A=3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3x=3x%2B2500 ALIGN=MIDDLE  ALT=\"3x=3x%2B2500\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply both sides by x\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0=2500 ALIGN=MIDDLE  ALT=\"0=2500\"   DISABLED_style= \"max-width:90%; height:auto;\" > Subtract 3x from both sides\r<BR>\n" );
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document.write( "Since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0=2500 ALIGN=MIDDLE  ALT=\"0=2500\"   DISABLED_style= \"max-width:90%; height:auto;\" > will never be true, this means that the average cost will never be equal to $3. So this also means that the average cost will never fall below $3 (since it never gets to $3)\r<BR>\n" );
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document.write( "e)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%283x%2B2500%29%2Fx ALIGN=MIDDLE  ALT=\"A=%283x%2B2500%29%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the average cost function\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5=%283x%2B2500%29%2Fx ALIGN=MIDDLE  ALT=\"5=%283x%2B2500%29%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=5 ALIGN=MIDDLE  ALT=\"A=5\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5x=3x%2B2500 ALIGN=MIDDLE  ALT=\"5x=3x%2B2500\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply both sides by x\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x=2500 ALIGN=MIDDLE  ALT=\"2x=2500\"   DISABLED_style= \"max-width:90%; height:auto;\" > Subtract 3x from both sides\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=1250 ALIGN=MIDDLE  ALT=\"x=1250\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by 2 to isolate x\r<BR>\n" );
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document.write( "So 1,250 animals must be tested to make the average cost to be $5.00 per animal  </SPAN>\n" );
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