Just for the record here, I dislike proper fractions.
It's not the concept, it's the form of the number. Something like "1 1/3" is likely to be misconstrued either as 11/3 or 1 times 1/3. The only saving grace to them is when it is typed in some sort of font such as , but this also can be taken to be .
I think overall it's much better just to leave it as 4/3.
By the way do you have a degree in mathematics?