1) Show the calculation to get the aspect ratio of an HD image at 1080 2) Provide a shell command "one liner" that I could use to list all of the files in a directory, only showing those that I own 3) Write a Python 2.7 function that takes a directory path, and prints the size, in bytes, of all the files ignoring sub-directories, reverse sorted by size, with the total in the following exact format