document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=974117>Question 974117</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This is such a long question, and it's worth 10 points. I feel like I'm headed in the wrong direction, please help.\r<BR>\n" );
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document.write( "The average cost of a new car has<BR>\n" );
document.write( "been changing approximately<BR>\n" );
document.write( "linearly with time. In 1990, the<BR>\n" );
document.write( "average cost was $16,950, and the<BR>\n" );
document.write( "average cost was $27,957 in 2008.\r<BR>\n" );
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document.write( "a) Let x = the number of years after<BR>\n" );
document.write( "1990 and let y = average cost of<BR>\n" );
document.write( "a new car. What ordered pairs<BR>\n" );
document.write( "can be written to express this<BR>\n" );
document.write( "information?\r<BR>\n" );
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document.write( "b) Write the equation of the line<BR>\n" );
document.write( "through these two points in<BR>\n" );
document.write( "point-slope form.\r<BR>\n" );
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document.write( "c) Convert the equation of the line<BR>\n" );
document.write( "to slope-intercept form and<BR>\n" );
document.write( "explain in your own words what<BR>\n" );
document.write( "the slope means in the context<BR>\n" );
document.write( "of this problem.\r<BR>\n" );
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document.write( "d) Based on this linear model, what<BR>\n" );
document.write( "will be the average cost of a new<BR>\n" );
document.write( "car in 2018?\r<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 #596146 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=596146\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a) (0, 16950), (8, 27957)<BR>\n" );
document.write( "b) slope m is (27957 - 16950) / (8 - 0) = 11007 / 8 = 1375.875<BR>\n" );
document.write( "use the point (8, 27957)<BR>\n" );
document.write( "(y-27957) = 1375.875(x-8)<BR>\n" );
document.write( "c) (y-27957) = 1375.875(x-8)<BR>\n" );
document.write( "y-27957 = 1375.875x - 11007<BR>\n" );
document.write( "y = 1375.875x + 16950<BR>\n" );
document.write( "The slope 1375.875 means that for each year after 1990, the averge cost of a new car increases by 1375.875<BR>\n" );
document.write( "d) now 2018 - 1990 = 28<BR>\n" );
document.write( "y = 1375.875x + 16950<BR>\n" );
document.write( "let x = 28, then<BR>\n" );
document.write( "y = 1375.875(28) + 16950<BR>\n" );
document.write( "y = 38524.5 + 16950<BR>\n" );
document.write( "y = 55474.5<BR>\n" );
document.write( "therefore the average cost of a new car in 2018 will be $55,474.50<BR>\n" );
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document.write( "makes me wonder how many unsold new cars will be in 2018<BR>\n" );
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