Nonsense! I was using them a mere 20 years ago! Never underestimate the antiquity of tertiary and quaternary backups used by the military!I don't think 10% resistors (E12 series) have been used since 50 years ago.
No.Gain = R3/R4.
This I know, if you read the entirety of this thread I did mention loading would make a difference. Even showed it in my calculations. Picky picky, choosing context.No.
The gain is R3/R4 only when there is no load. The circuit has a 10k collector resistor (R3) and a 10k load so the gain is half.