Problem 2 of 3, embed.ly challenge

stdiv.hs

--list of <p> tag depths
ps = [1,2,1,1,1,1,1,1,1,2,2,2,3,3,3,4,4,4,4,4,5,5,5,5,1,1,1,1,1,2,1,1,1,1,2,2,1,3,1]

--compute mean of data points
avg = x/y
	where
		x = sum ps
		y = fromIntegral(length ps)

--computes difference of data point and mean, square the result
diffSq p = (p - avg)^2

--computes the std divation by taking the average of diffSq results, then taking the sqrt
stdiv = sqrt(x/y)
	where
		x = sum (map diffSq ps)
		y = fromIntegral(length ps)

main = putStrLn (show stdiv)