Changing hit weights moves the centroid toward the heavier cell. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Moving weight shifts the centroid
Now the left weight is 1 and the right weight is 3.
1×1+3×2=7
The new centroid is seven over four meters
The same total weight 4 gives a centroid of 7 over 4 meters.