C# 标准差计算

            if (numberList.Any())
            {
                exEntity.MinValue = numberList.First().NumberValue.ToString();
                exEntity.MaxValue = numberList.Last().NumberValue.ToString();
                exEntity.AvgValue = Math.Round((decimal)numberList.Average(p => p.NumberValue), 5).ToString();
                //标准差
                if (numberList.Count > 1)
                {
                    double sumOfSquare = 0; //平方总和
                    foreach (var item in numberList)
                    {
                        double numberValue = double.Parse(item.NumberValue.ToString());
                        sumOfSquare += Math.Pow((numberValue - double.Parse(exEntity.AvgValue)), 2);
                    }
                    double stdDeviation = Math.Sqrt(sumOfSquare / (numberList.Count - 1));
                    stdDeviation = Math.Round(stdDeviation, 5);
                    exEntity.StdDeviation = stdDeviation.ToString();
                }
            }