>>154
なんとか動いてます。
value :: [Float] -> [Float]
value [] = []
value (x:xs) = case (ave (x:xs) /= 0) of
True -> (x/ave (x:xs)) : value xs
False -> []

ave :: [Float] -> Float
ave (x:xs) = (sum (x:xs)) / (fromIntegral (length (x:xs)))
ave [] = 0