Thanks to everyone who partipated in our mathlympics related to the Jesus statue! So, pretty much, thanks to Jeff Feely.
His second answer, of 8.33ish, is the one I was seeking, though technically the first answer (Jesus should be wearing the 7) is also correct, in a manner of speaking.
Here is how we addressed it:
My own approach was less orthodox. I tried to go the route of the geometric mean, in which 7:x = x:10, => x^2 = 70 => x=8.3666. If this is the correct solution, then 8.3666*12 = 10^2. We see that 8.3666*12 is actually 100.3992, the square root of which is 10.0199. Oooh, so close but not exact!
Note: Yes, I was all wrong. Serves me right for trying to assume a geometric relationship in an arithmetic number sequence.
7 + 1.33333 = 8.3333
8.33333 + 1.6666667 = 10
10 + 2 = 12
So increments of 1.3333, 1.66666, 2.
Like Lost I guess, except my numbers make sense!
Made a graph.