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"));
}
