input: Write a function to create a Python dictionary that stores data about a student. The dictionary should include the student's name, year, GPA, list of courses, and a list of extracurricular activities. If the input is valid, return the dictionary; otherwise, return None.
  assert create_student_data({}, 'John Smith', 'Freshman', 3.25, ['math', 'english', 'Computer Science', 'Statistics'], ['Chess Club', 'Student Government', 'Debate Team'])=={
      'name': 'John Smith',
      'year': 'Freshman',
      'gpa': 3.25,
      'courses': ['math', 'english', 'Computer Science', 'Statistics'],
      'extracurricular': ['Chess Club', 'Student Government', 'Debate Team']
  }
  assert create_student_data({}, '', '', 0.0, [], [])==None
  assert create_student_data({}, None, 'Sophomore', 3.5, ['physics'], ['Basketball'])==None
  assert create_student_data({}, 'Jane Doe', 'Junior', 4.0, ['history', 'chemistry'], ['Music Band'])=={
      'name': 'Jane Doe',
      'year': 'Junior',
      'gpa': 4.0,
      'courses': ['history', 'chemistry'],
      'extracurricular': ['Music Band']
  }
output: def create_student_data(student_dict, name, year, gpa, courses, extracurricular):
      if not name or not year or not isinstance(gpa, (int, float)) or not courses or not extracurricular:
          return None
      student_dict['name'] = name
      student_dict['year'] = year
      student_dict['gpa'] = gpa
      student_dict['courses'] = courses
      student_dict['extracurricular'] = extracurricular
      return student_dict