public override Evaluation GetEvaluation(double correctValue) { var meanValue = Readings.Average(x => x.Value); var meanMistake = Math.Abs(meanValue - correctValue); var standardDeviation = Math.Sqrt(Readings.Sum(x => Math.Pow(meanValue - x.Value, 2)) / (Readings.Count - 1)); string result; if (meanMistake > 0.5) { result = "precise"; } else if (standardDeviation > 3) { result = "very precise"; } else { result = "ultra precise"; } return(new Evaluation(Name, result)); }