document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=330600>Question 330600</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In 1920, the record for a certain race was 46.7 seconds in 1940, it was 46.1 sec. Let R(T)= the record in the record in the race and t=the number of yes since 1920\r<BR>\n" );
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document.write( "A. find a linear function that fits the data \r<BR>\n" );
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document.write( "b. Use the function in (a) to predict the record in 2003\r<BR>\n" );
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document.write( "c Find the year when the record will be 43.88 seconds </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #237049 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=237049\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In 1920, the record for a certain race was 46.7 seconds in 1940, it was 46.1 sec.<BR>\n" );
document.write( " Let R(T)= the record in the record in the race and t=the number of yes since 1920<BR>\n" );
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document.write( "A. find a linear function that fits the data<BR>\n" );
document.write( "Find the slope, assign the given value as follows:<BR>\n" );
document.write( "x1=0, y1=46.7; (1920)<BR>\n" );
document.write( "x2=20,y2=46.1; (1940)<BR>\n" );
document.write( "slope(m) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2846.1-46.7%29%2F%2820-0%29 ALIGN=MIDDLE  ALT=\"%2846.1-46.7%29%2F%2820-0%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-.6%2F20 ALIGN=MIDDLE  ALT=\"-.6%2F20\"   DISABLED_style= \"max-width:90%; height:auto;\" > = -.03<BR>\n" );
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document.write( "the point/slope equation; y - y1 = m(x - x1)<BR>\n" );
document.write( "y - 46.7 = -.03(x - 0)<BR>\n" );
document.write( "y = -.03x + 46.7<BR>\n" );
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document.write( "R(t) = -.03t + 46.7, is the function<BR>\n" );
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document.write( "b. Use the function in (a) to predict the record in 2003<BR>\n" );
document.write( "2003 - 1920 = 83; t=83<BR>\n" );
document.write( "R(83) = -.03(83) + 46.7<BR>\n" );
document.write( "R(83) = -2.49 + 46.7<BR>\n" );
document.write( "R(83) = 44.21 sec in 2003<BR>\n" );
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document.write( "c Find the year when the record will be 43.88 seconds<BR>\n" );
document.write( "-.03t + 46.7 = 43.88<BR>\n" );
document.write( "-.03t = 43.88 - 46.7<BR>\n" );
document.write( "-.03t = -2.82<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-2.82%29%2F%28-.03%29 ALIGN=MIDDLE  ALT=\"%28-2.82%29%2F%28-.03%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = +94 yrs<BR>\n" );
document.write( "1920 + 94 = 2014 the yr it should be 43.88 sec </SPAN>\n" );
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