Chemistry HW question help!?

http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/electpot.html
Refer to the above webpage for standard reduction potentials.
Different answer would be obtained for different source of standard reduction potentials used.

Mg²⁺(aq) + 2e⁻ → Mg(s) .… E° = -2.38 V
Fe²⁺(aq) + 2e⁻ → Fe(s) …. E° = -0.41 V

Mg(s) + Fe²⁺(aq) → Mg²⁺(aq) + Fe(s) …. E°(cell) = (-0.41) - (-2.38) V = +1.97 V

E(cell)
= E°(cell) - (RT/zF) ln([Mg²⁺]/[ Fe²⁺])
= +1.97 - {8.314 × (273.16 + 25.00) / 2 × 96500} ln (0.815/0.0180) V
= +1.92 V