You research the average cost of a tank of gasoline for a certain type of car for several recent years to look for trends. The table shows your data. What is the equation for a line of best fit? How much would you expect to pay for a tank of gas in the year 2019? Let x be the number of years after 1998.

Question

You research the average cost of a tank of gasoline for a certain type of car for several recent years to look for trends.  The table shows your data.  What is the equation for a line of best fit?  How much would you expect to pay for a tank of gas in the year 2019? Let x be the number of years after 1998.

anonymous · Answer

Year	 1998	2000 	2002 	 2004	2006 	2008 
Average cost for one tank ($)	 $26.40	 $27.20	 $29.70	 $29.30	 $32.20	 $37.80

anonymous · Answer

A y = 1.006x + 26.40; $47.52
B y = 1.006x + 26.40; $58.92
C y = 26.40x + 1.006; $47.52
D y = 26.40x + 1.006; $58.92

anonymous · Answer

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Gradient : 
we need 2 coordinates ... for example : ( 29.30 , 2008 ) and ( 26.40 , 1998 )
Gradient , m : 
Y - y1 divide X -x1 
can you carry on now ?