public StandartSapma(int n, float [] sayilar)
        {
            AritmetikOrtalama aO = new AritmetikOrtalama(sayilar, n);
            float             ust = 0, xbar = aO.Sonuclu(sayilar, n);

            for (i = 0; i < n; i++)
            {
                ust += Convert.ToSingle(Math.Pow((sayilar[i] - xbar), 2));
            }
            float sonuc = Convert.ToSingle(Math.Sqrt(ust / n));
        }
        private void button4_Click(object sender, EventArgs e)
        {
            int n = listBox1.Items.Count;

            float[] sayilar = new float[n];
            for (int i = 0; i < n; i++)
            {
                sayilar[i] = Convert.ToSingle(listBox1.Items[i].ToString());
            }
            AritmetikOrtalama aO = new AritmetikOrtalama(sayilar, n);

            listBox1.Items.Clear();
            listBox1.Items.Add("-------------" + aO.Sonuclu(sayilar, n));
        }