How much football is there in an American football game?

This weekend there is a virtual marathon of football being served up by the National Football League, four playoff games in two days (about 12 plus hours of viewing). An NFL football game is separated into four quarters of fifteen minutes each to bring the fan an hour of football. This becomes anywhere from 3 to 3.5 hours of viewing time with all the breaks and stoppages in a game. The question is, how much is the ball actually in play during an NFL football game. The answer, which may surprise you, is after the jump.

According to this WSJ article, the mean amount of time the football is actually in play in an average NFL game is approximately 11 minutes.