(the change in 'y') divided by (the change in 'x') .
This line is so easy ... it crosses all the corners of the boxes, so you have tons of choices of what 2 points to pick. But let's just pick the ends of the line.
From the beginning to the end of the line:
-- the change in 'y' is 4 meters
-- the change in 'x' is 40 seconds
Slope = (the change in 'y') divided by (the change in 'x') .
