For the given cell
${\rm{F}}{{\rm{e}}^{2 + }}_{\left( {{\rm{aq}}} \right)} + {\rm{Ag}}_{\left( {{\rm{aq}}} \right)}^ + \to {\rm{F}}{{\rm{e}}^{3 + }}_{\left( {{\rm{aq}}} \right)} + {\rm{A}}{{\rm{g}}_{\left( {\rm{s}} \right)}}$
The standard cell potential of the above reaction is
Given:
${\rm{A}}{{\rm{g}}^ + } + {{\rm{e}}^ - } \to {\rm{Ag}}$ $~~{E^\theta } = xV$
${\rm{F}}{{\rm{e}}^{2 + }} + 2{{\rm{e}}^ - } \to {\rm{Fe}}$ $~~{E^\theta } = yV$
${\rm{F}}{{\rm{e}}^{3 + }} + 3{{\rm{e}}^ - } \to {\rm{Fe}}$ $~~{E^\theta } = zV$