Lesson 9: scene 1 - added a new Array
Lesson 9: scene 2 - combined three arrays into one interface array
Lesson 8: scene 3 - added a new object to the Drawable interface
Lesson 9: scene 4 - added a second interface
Lesson 9: scene 5 - implemented an instanceof test and a cast
Lesson 9: measure 1 - calculated the average population of an array of Countries
Lesson 9: measure 2 - calculated the average of fuel efficiency for a group of cars
Lesson 9: measure 3 - added the Measurable interface to eliminate duplicate code when calculating an average