I would say within arms reach of the toilet. preferably on the right side. No. If the toilet is near the corner of the room, then the wall that the toilet ISNT laying against is the place for the...
4 inches
There is no "AVERAGE" per-se however, 30 to 36 inches high and 6 to 10 inches in front of the toilet works well. These measurements are to centerline of the roll.
There are limits...