<PRE><B>Question 136991</B>
The line y=0.15x + 0.79 represents an estimate of the average cost of gasoline for each year.
The line 0.11x - y= -0.85 estimates the price of gasoline in January of each year (Bureau of Labor Statistics, 2006). 
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y = 0.15x + 0.79
y = 0.11x + 0.85
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a) Do you expect the lines to be intersecting, parallel, or perpendicular? Explain your reasoning. 
The slopes are different so the lines intersect.
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b) Use the equations of the lines to determine if they are parallel. What did you find? 
They are not; they intersect.
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c) Did your answer to part b confirm your expectation in part a? 
Yes
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{{{graph(400,300,-10,10,-10,10,0.15x+0.79,0.11x+0.85)}}}
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Cheers,
Stan H.

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