The April 22, 1991 issue of Aviation Week and Space Technology reports that during Operation Desert Storm,

Question:

The April 22, 1991 issue of Aviation Week and Space Technology reports that during Operation Desert Storm, U.S. Air Force F-117A pilots flew 1270 combat sorties for a total of 6905 hours. What is the mean duration of an F-117A mission during this operation? Why is the parameter you have calculated a population means?