Steve misunderstood the line of best fit.
The line of best fit is a straight line drawn on plotted points in a Cartesian plane in such a way that it divide the points into approximately equal number on the other sides of the line. This is applicable to plotted points that are not linear i.e cases in which some of the points are scattered.
Therefore it is evident that Steve does not understand how to draw a line of best fit on the plotted points.