help please with the sort and average question

* Retrieve a list, sorted in increasing order, * the information objects of all stored passengers. * Hints: * 1. Override the compareTo' method in PassengerInfo class. * 2. Look up the Arrays.sort method in Java API. * @return A sorted list of information objects of all passengers. public PassengerInfo[] getSortedPassengerInfo() { /** * Retrieve the average ticket paid by all passengers in flight with id 'id'. * @param id id of some flight * @return average ticket paid by all passengers in a flight with id 'id' * @throws IdNotFoundException if id is not an existing flight id */ public double getAverageTicketAmount (Integer id) throws IdNotFoundException { @Test public void test_getSortedPassenger Info_normal() { addFlights(); addPassengers(); PassengerInfo[] sorted = db.getSortedPassengerInfo(); PassengerInfo[] expected = { new PassengerInfo("Heeyeon", 10, 2000), new PassengerInfo("Sunhye" 30, 2577), new PassengerInfo("Jiyoon" 50, 2577), new PassengerInfo("Yuna" 50, 990), new PassengerInfo("Suyeon" 70, 2577), new PassengerInfo("Jaebin" , 70, 2000), new PassengerInfo("Jihye" , 70, 990), assertEquals(7, sorted.length); assertArray Equals(expected, sorted)