Andrew opened a car wash station in his neighborhood. He recorded the number of cars washed each week for the first six weeks. The data are shown as a scatter plot below.

Question

gabylovesyou · Answer

Based on the line of best fit, which of these would be the best prediction for the number of cars washed in Week 8?

 4

 9

 16

 18

gabylovesyou · Answer

@SmoothMath

anonymous · Answer

can you find the equation of the line ?

gabylovesyou · Answer

how?

anonymous · Answer

you have a point 0,0 on the graph and
4,9

anonymous · Answer

Not even necessary. Just look at where the line is going. What y value does it make sense that it would be at for week 8?

anonymous · Answer

using two points .. you find the slope 
m = (y1 - y2) /(x1-x2) = (9-0)/(4-0) = 2.25

now in order to get the equation of the line :
y = y1 + m(x-x1)
we choose one of the points so we choose 0,0 since its easier to work with
y = 0 + 2.25(x-0)
y = 2.25x

in week 8 there will be
y = 2.25 * 8 = 18