The school is planning for the next commencement and has the following estimates to work with.

There are 409 students on average every commencement. The school wishes to complete the commencement exercise within an hour. An average of 12 students are hooded per minute. Names are called @ one student every 7 seconds. The walk to go to the center of the stage, and physically receive the diploma, takes a student 8.2 seconds, on average. It takes an additional 2 seconds for a student to walk on and exit. There are 5 students on stage, on average - some being hooded, some waiting for their names to be called, some walking to receive their diplomas, and some exiting the stage.

What is the average flow time of a unit in seconds per student?