This reminds me of the 3b1b about average shadow.
Similar question is average depth of a cube in that direction . Volume = Depth * Shadow
D = V / S = V / (A/4) = 8 / (24 / 4) = 4/3
A point in the cube, on average is closer than 4/6 to a face, half of the depth. the answer is therefore ≤ 4/6

This is me alarmed, discovering that Unity uses Left Handed coordinates

I always assumed it was only valid for single character fractions. ½¼⅔ etc. They aren't a division but just a character/digit that has the value of "one half" etc
regular fractions after a number should DEFINITELY not follow this and I don't think (I hope) not many things actually use it that way