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Question 974048: Average cost of a new car has been changing approximately linearly with time. In 1990, the average cost was $16,950, and the average cost was $27,957 in 2008. Let X= number of years after 1990 and let Y= average cost of a new car. A) What ordered pairs can be written to express this information? and B) write equation of the line through these points in point slope form.
I set up ordered pairs as (1990, 16790) (2008, 27957). I labeled ordered pairs as X1,Y1 and X2,Y2, respectively to solve for the slope. Once I get slope can solve for equation of line using slope intercept formula Y= mx +b. I believe my order pairs are not correct and therefore my slope not correct and can not find error. Please provide assistance with correct ordered pairs and help with equation of the line through the ordered pairs two points in point-slope form.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Average cost of a new car has been changing approximately linearly with time.
In 1990, the average cost was $16,950, and the average cost was $27,957 in 2008.
Let X= number of years after 1990 and let Y= average cost of a new car.
A) What ordered pairs can be written to express this information? and B) write equation of the line through these points in point slope form.
Set up ordered pairs as (0, 16790) (18, 27957).
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slope = (27957-16790)/(18) = 620.39
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Note that the y-intercept is 16790.
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Equation:
Y = 620.39X + 16790
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Cheers,
Stan H.
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