document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=184129>Question 184129</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a group of biologists studied the nutritional effects on rats that were fed a diet containing 10% protein.  the protein was made up of yeast and corn flour.  by changing the percentage P ( expressed as a decimal ) of yeast in the protein mix, the group estimated that the average weight gain g (in grams) of a rat over a period of time was given by \r<BR>\n" );
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document.write( "g= -200p^2 + 200p + 20\r<BR>\n" );
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document.write( "what percentage of yeast gave an average weight gain of 60 grams ?<BR>\n" );
document.write( "I need the answer with steps please, thanks  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #138151 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=138151\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> g= -200p^2 + 200p + 20 <BR>\n" );
document.write( "what percentage of yeast gave an average weight gain of 60 grams ?<BR>\n" );
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document.write( "60 = -200p^2 + 200p + 20\r<BR>\n" );
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document.write( "-200p^2 + 200p - 40 = 0\r<BR>\n" );
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document.write( "-5p^2 + 5p - 1 = 0\r<BR>\n" );
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document.write( "p = [-5 +- sqrt(25 - 4*-5*-1)]/-10\r<BR>\n" );
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document.write( "p = [-5 +- sqrt(5)]/-10\r<BR>\n" );
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document.write( "p = [-5 - sqrt(5)]/-10\r<BR>\n" );
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document.write( "p = 0.7236 = 72.36%<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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