First off, just FYI... Currently the average male height for males in the US and UK is 5'9" or 69" although I have found other reports of UK males being 70" around the time of the A New Hope filming.
Not sure why you are rounding down 16.68223675 to 16 when it is closer to 17. However, for people who are doing Red 5 using Mark's height of 68" (5'8") and a more precise measurement of 16.682 scale. A Luke Skywalker figure would need to be 4.076" or 10.35304cm or 41/16".
...
I can't speak for the good people of NAS Jacksonville, but, as far as average heights, I personally stand right about 6' even, and in my corner of the USA, I'm not three inches taller than the average guy. In fact, I'm pretty much the average height, so I dunno how a 5'9" average was calculated.
But someone upthread suggests figuring scale based, not on the official LFL figure of 12.5 meters, but the studio scale X-Wings being 1:24 scale. So, how long were the studio scale X-Wings? Turns out I don't actually know definitively. But I have a number lodged in my head that I can't seem to verify of 24 inches. (PLEASE correct me if I'm wrong... I really would like to know the correct answer.)
So, a 24 inch long model at 1:24 scale would mean the full size would be 48 feet long. A 29.5 inch model of a 48 foot long subject would be closer to 1:19 scale than 1:16. It turns out that a 3.75 inch action figure is fairly close to 1:19 scale. To, the 29.5 inch X-Wing might well fit a 3.75 inch pilot figure.
Let's see how it looks.
Here's the Black Series Biggs figure (I got Biggs because he was the only one the store I went to had. I'll either convert this figure to be Luke (losing the mustache, remarking the helmet) or finding a proper Luke figure at another store.)
Here's a full scale Mark Hamill sitting in the cockpit set-piece.
And here's the 3.75" Biggs figure positioned in the 29.5" X-Wing fuselage.
I think he looks pretty good in there! The arch formed by the back of the canopy seems to frame the Biggs figure similarly to the framing of the full-size canopy over Mark Hamill's head.
And, really, kudos to the toy-designers at Hasbro! It seems like they scaled their X-Wing to fit their figures matching the sets seen in the films rather than fitting the official LFL numbers. Seems like every time I look into the official numbers, I find that they're basically arbitrary. I'm increasingly of the opinion that the official numbers probably shouldn't even be referenced as they're consistently wrong.
SO! I am recanting my initial 1:16 reckoning and I am now backing 1:19, which fits the 3.75" figures and makes finding appropriately sized pilots much simpler.
--Alex