Answer: y = -0.2x+13
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Step-by-step explanation:
To find the slope, all you need are two points.
Pick any two columns to form the two points. Once you have your two points, use the slope formula
I'll use the first two columns
m = (y2-y1)/(x2-x1)
m = (12.2-13)/(4-0)
m = -0.8/4
m = -0.2 is the slope
The y intercept is b = 13 since x = 0 leads to y = 13 (column 1)
With m = -0.2 and b = 13, we go from y = mx+b to y = -0.2x+13