static void Main(string[] args) { Book.Describe(); // public static method only accessible to class Book GradeBook = new Book("Spring 97 Algebra I (Ms Greenlaw)"); GradeBook.Name = "Spring '97 Algebra I (Mrs. Greenlaw)"; GradeBook.AddGrade(69); GradeBook.AddGrade(75); GradeBook.AddGrade(92); GradeBook.AddGrade(77); GradeBook.AddGrade(46); GradeBook.AddGrade(87); GradeBook.AddGrade(94); GradeBook.AverageGrades(); }