Simplified Nernst equation

[Grace_Stevenson_1A]

Could anyone explain how to get .0256... because every time I calculate R times T divided by F i get a different number

[Catherine_L_1C]

R(8.314) times T(298) divided by F (96485.3) should give you 0.02567823285, which is slightly off from what the answer key says, but should be acceptable for the following calculations. I believe on some of the equation sheets we were given with our course readers Faraday's constant looks like 964853 instead of 96485.3, so that could be the issue you're having.
Hope that helped!