Which is a better buy - A small banana or, a large one? (size matters, a little)

[inavalan]

On the "thenakedscientists" forum somebody wrote:

• This post made me curious.  We eat a banana every day with our meusli so I weighed and measured every one, then the skin, and set up an Excel sheet to calculate the result.
  A 27cm [10 1/2"](excluding stalk) has 3.5% more useful fruit, per gram, than a 19.5 cm [7 1/2"] banana.
  It is technicaly better, then, to get bigger ones but practicaly, best to just get the size to suit yourselves. 
  Incidentaly, the larger bananas had twice as much weight of useful fruit than the small.