I'm reluctant to say "of course" but of course it's possible.
That said, I don't think it can be denied that if you were to study those actively pursuing FI/RE as a whole you would find that their incomes are considerably above mean/median levels, and for most of us it is still a fairly long and hard slog, so it can only be longer and harder still for those on average or below average incomes. I earn a well above "average" UK salary, but on these boards I quite often feel like an underachiever when I read how well others are doing.
Jakob Fisker claims (and I well believe him) to get by on $7k pa. That said, he is able to do so because he's a not only frugal, but intelligent and resourceful. These qualities can drive down your living cost to very low figures.
Personally with a paid off home and no dependents I could live on $7kpa. I suspect most people could if they were forced to, after a period of adjustment. But I would find it restricting, and the point of FI is the opposite of that, it's to enjoy financial freedom, not impose financial restraint.
IMO if you desire financial freedom then you should seek to increase your income once you have your spending habits sorted out. That may not be what you want to hear if you are stuck on a lower salary, but the market rewards hard work and productivity and there is no reason why if you do not work hard and apply yourself you can become productive enough to earn an above average wage. If you have above average goals then you should seek to be an above average employee. Personal development is the key.