Honestly, given the roundness of 7.5 ft, I would assume that 7.5 ft was the estimate and it was improperly converted to 2.29m as a precise measure.
With the unusualness of a European measuring something in feet.
It always irks me when I see signs saying "keep 6 ft (1.8288 m) apart", because 6 feet is just a round number of the approximate distance, and it's fine to just say "keep 6 ft (2 m) apart", for all that you'll get weirdos going "Well which is it??? 6 feet or 2 meters????"
