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), ).ToString();
                 //标准差
                 if (numberList.Count > )
                 {
                     double sumOfSquare = ; //平方总和
                     foreach (var item in numberList)
                     {
                         double numberValue = double.Parse(item.NumberValue.ToString());
                         sumOfSquare += Math.Pow((numberValue - double.Parse(exEntity.AvgValue)), );
                     }
                     double stdDeviation = Math.Sqrt(sumOfSquare / (numberList.Count - ));
                     stdDeviation = Math.Round(stdDeviation, );
                     exEntity.StdDeviation = stdDeviation.ToString();
                 }
             }