6Ö`7.................how in the world do you figure this out???

Answer 1

If I translate your question to the 'Symbol' font I get:
6√7

So I don't know if you meant 6 times sqrt(7) or if you meant the sixth root of 7.

CASE 1:
6 times sqrt(7) --> take the square root of 7 and multiply it by 6 ≈ 15.8745079

CASE 2:
6th root of 7 --> equivalent to 7 to the (1/6) power. Also equivalent to sqrt(cube root(7)) ≈ 1.38308755