static void Main(string[] args) { Student joe = new Student("Joseph", "Smith", 17, 3.45); Student mary = new Student("Mary", "Jones", 16, 3.75); Student alice = new Student("Alice", "Wilson", 18, 3.55); double averageGPA; double averageAge; joe.display(); mary.display(); alice.display(); averageAge = (joe.getAge() + mary.getAge() + alice.getAge()) / 3.0; averageGPA = (joe.getGPA() + mary.getGPA() + alice.getGPA()) / 3.0; Console.WriteLine("Average age: " + averageAge.ToString("f2")); Console.WriteLine("Average GPA: " + averageGPA.ToString("n2")); }