let variancetest values = 

    let average = Seq.average values

    let length = Seq.length values

    values |> Seq.iteri(fun i x -> printfn "%i [%f]: %f ^ 2 = %A" i  x (x - average) ((x - average) ** 2.0))

    let sum = values

               |> Seq.map (fun x -> (x - average) ** 2.0)

               |> Seq.sum

​

    let flength = float length

    printfn "Sum = %f" sum

    printfn "1/length = %f" (1.0 / flength)

    printfn "Result / length = %f" (sum / flength)

​

variancetest [1.0..6.0]