200 g in the ratio 8 : 3 : 2 is approx 123 g, 46 g and 31 g.

We will call the golden ratio, 1.618033989:1, G. G2-1=G; 1/G+1=G; (1+G)/G=G; For more, research golden ratio on wikipedia.

1 mole of water is equal to 18 g.
2 g hydrogen is equal to 22,25 L.
16 g oxygen is equal to 11,2 L.
The volumes ratio H/O is approx. 2.

Let us use Sn = u + 1/2 a [2n-1]

For n = 4, S4 = 0 + 1/2 g . 7 = 7/2 g

For n = 5, S5 = 0 + 1/2 g . 9 = 9/2 g

So required ratio S4/S5 = 7/9

That is the shear modulus, G, related to Young elastic modulus ,E, as G = E/(2(1+u)) where u is Poisson ratio