Sorry to disturb old answers but in the accepted answer there is some confusion.
( 1.5 + 2.5 + 3.5 ) / 3 = 2.5
Scool rounding: ( 2 + 3 + 4 ) / 3 = 3
'Bankers' rounding: (I'm confused how 1.5 and 2.5 becomes 2, 2)
                ( 1 + 2 + 3 ) / 3 = 2
And values are still correct. If we are to continue 
scool rounding 2.5 -> 3
bankers rounding 2.5 -> 2
So in the example there's no clear understanding why MidpointRounding.ToEven is used over AwayFromZero.