Estimate the Value of K_f for Hexafluoroaluminate Using the Following $\to$

Estimate the value of K_f for hexafluoroaluminate using the following standard reduction potentials as needed.
AlF₆^-(aq)+ 3 e^- $\to$ Al(s)+ 6 ^-(aq) $\quad$ E° = -2.069 V
Al³⁺(aq) + 3 e^- $\to$ Al(s) $\quad$ $\quad$ $\quad$ $\quad$ E° = -1.662 V
F₂ (g)+ 2 e^- $\to$ 2 F^-(aq) $\quad$ $\quad$ $\quad$ $\quad$ E° = +2.866V