static void Main(string[] args) { var book = new Book { Name = "Grade Boo" }; book.AddGrade(89.54); book.AddGrade(56.8); book.AddGrade(32.23); var statistic = book.GetStatistic(); Console.WriteLine($"the low is {statistic.Low}"); Console.WriteLine($"the high is {statistic.High}"); Console.WriteLine($"the average is {statistic.Average:N}"); }