Public Class Form1
Public n, sumx, sumxx As Integer
Private Sub cmdLisa_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdLisa.Click
n = n + 1
sumx = sumx + Val(txtSisestus.Text)
sumxx = sumxx + Val(txtSisestus.Text) * Val(txtSisestus.Text)
lblN.Text = n

End Sub

Private Sub cmdArvuta_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdArvuta.Click
lblKv.Text = sumx / n
Dim vahe As Double
vahe = Math.Abs((n * sumx - sumxx) / n * (n - 1))
lblbStd.Text = Math.Sqrt(vahe)
End Sub

End Class