Very hard to state an average IMO
Open run in a box room or annoying little hallways with turns, closets, radiators or floor vents?
Does that mean a 7.5 hours non-stop with a half hour lunch break?
That can get real old after day 3.
Seems like the first 4 starter and last rows can take just as long as 50 rows in the middle of a small room sometimes.
Are we talking about prep too?
-Comfort discussion with customer and 20 questions?
-Hauling tools in & out. (long front walk up 15 steps and rooms on 2nd floor of house?)
-Hanging plastic
-Dealing with subfloor squeaks.
-Cutting door jambs.
-Sweeping & scraping up all the crap left over from the electrician, plumber and spacklers.
-Shop vac the edges or possibly the entire floor.
-Don't forget about carefully removing existing base molding, numbering all the pieces and pulling all the nails out because it has to be reinstalled.
I like to rack out the entire floor before we start to nail. That can take quite a while in a big room. I know some guys only like rack a foot out but that's too annoying for me.
Hell, all that stuff I listed can take as long or longer then the actual field install and a pissy annoying job may end up with only 200' going down.
All that aside, if the whole thing is prepped, racked, set up and ready to nail from row 5 and on in a giant box room - I would think one guy should do at least 500'-600' of 3".
Posib more but I know other stuff will suck up time and its hard pressed to get a non-robot worker to go full blast all day every day.