The gravitational force between a mass and the Earth is the object's weight. Mass is considered a measure of an object's inertia, and its weight is the force exerted on the object in a gravitational field. On the surface of the Earth, the two forces are related by the acceleration due to gravity: Fg = mg.
If you observe very closely, 55 would end up being closer to 60 than towards the middle. 48 lines up with the "disturbance of the force" more so than 55.
