3.5

        private static void StudentStats(StudentSystemDBContext context)
        {
            var students = context.Students
                .OrderByDescending(x => x.Courses.Sum(z => z.Price))
                .ThenByDescending(c => c.Courses.Count)
                .ThenBy(s => s.Name)
                .ToList();

            Console.WriteLine($"Total students: {students.Count}");
            foreach (var student in students)
            {
                Console.WriteLine($"Name: {student.Name}, Courses: {student.Courses.Count}, Price: {student.Courses.Sum(x => x.Price)}, Average: {student.Courses.Average(a => a.Price)}");
            }
        }