Answer:
It’s a quite good approximation to the “golden ratio” a.k.a. ϕ whose exact value is ( 5√+12 ) which a pretty remarkable number. In fact it is a solution to the equation x2=x+1 , (the other solution is just ϕ−1 which is the same as 1ϕ , another remarkable identity).
| Multiply both sides by 8.5
| Multiply 1.618 and 8.5
