Finding the average of three numbers in haskell

averageThree :: Float -> Float -> Float -> Float

averageThree  a b c = (a + (b + c))/3.0

isAbove :: Float -> Float -> Int

isAbove a avg

 | a > avg = 1

 | otherwise = 0

numAbove :: Float -> Float -> Float -> Int

numAbove a b c = (isAbove a avg) + (isAbove b avg) + (isAbove c avg)

  where

   avg = averageThree a b c