statistics.hs

import Data.List

media :: Fractional a => [a] -> a
media l = sum l / (fromIntegral $ length l)

desvios :: Fractional a => [a] -> a -> [a]
desvios xs m = map (subtract m) xs

powtwo :: Fractional a => [a] -> [a]
powtwo = map (^2)

variancia :: Fractional a => [a] -> a
variancia xs = (sum $ powtwo $ desvios xs $ media xs) / (fromIntegral $ length xs - 1)

desvioPadrao :: Floating a => [a] -> a
desvioPadrao = sqrt.variancia