document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=571138>Question 571138</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help solving this word problem...I have been trying for 2 hours.\r<BR>\n" );
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document.write( "In 1920, the record for a certain race was 45.4 sec. In 1970, it was 44.4 sec. \r<BR>\n" );
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document.write( "Let R(t)=the record in the race and t=the number of years since 1920.\r<BR>\n" );
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document.write( "Find a linear function that fits the data<BR>\n" );
document.write( "R(t)=<BR>\n" );
document.write( "Round to nearest hundredth\r<BR>\n" );
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document.write( "What is the predicted record for 2003____sec<BR>\n" );
document.write( "What is the predicted record for 2006?<BR>\n" );
document.write( "In what year will the predicted record be 43.50 seconds?\r<BR>\n" );
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document.write( "Thanks so much! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #367965 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=367965\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> year		Record time					<BR>\n" );
document.write( "1920		45.4	seconds				<BR>\n" );
document.write( "1970		44.4	seconds				<BR>\n" );
document.write( "Difference							<BR>\n" );
document.write( "50		-1					<BR>\n" );
document.write( "rate of reduction per year =-1	/50	=	-0.02<BR>\n" );
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document.write( "R(t)=	45.4-0.020t 			<BR>\n" );
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document.write( "2003	t=83					<BR>\n" );
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document.write( "R(t)=	45.4	+	-0.020	*	83		<BR>\n" );
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document.write( "R (83)=	43.74	seconds		\r<BR>\n" );
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document.write( "------------<BR>\n" );
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document.write( "R(t)=	45.4-0.02t <BR>\n" );
document.write( "43.5=45.4-0.02t<BR>\n" );
document.write( "45.4-43.5=0.02t<BR>\n" );
document.write( "1.9=0.02t<BR>\n" );
document.write( "t= 1.9/0.02<BR>\n" );
document.write( "t=95 years\r<BR>\n" );
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document.write( "1920 +95 = 2015\r<BR>\n" );
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document.write( "year 2015  it will bve 43.5 seconds </SPAN>\n" );
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