How much can a chess COACH boost the ratings of an experienced player?

I was wondering, how much could the rating of an EXPERIENCED player increase after being coached by another player who has a much higher rating and is has more experience?

For instance, I consider myself experienced because: I read about 7 classic books, carefully analyzing all games in those books, and played a few OTB tournaments. This was a long time ago.

According to me its about players dedication the more dedicated the more productive coach is

@Mahith1708 yes sure. But can you guess any number figure?

If the student is highly dedicated, then I feel like the coach will only be helping him to accomplish his goal faster. A goal he could accomplish by himself anyway. Is this right?

#3
There's no certain number, unless you're looking for the average of how many points people have gained with a coach.
For me, my OTB rating increased by 200, but I'm pretty sure it should be more, because without my coach I kept tilting and didn't even have a full opening repertoire. So I'd say my strength increased by ~400 points after taking lessons for a year.
Some coaches have their limits, and can't teach students once they get to a certain level. But even Carlsen has a coach, and he's still improving everyday. Undedicated students may quit within a year or two, while some dedicated ones may reach the GM level.
In my opinion, how much you learn usually depends on how many hours you put in, as with most other activities.

@FriskyCyclops, thanks a lot for your answer. Boosting +400 seems incredible, if that's possible. That would put me in the top end of Lichess classical leaderboard. Because I can already reach 2200 by myself, even though I never took lessions.

But here goes an important question. Were you already experienced before getting the lessions?
PS: With experienced, I mean someone who has played OTB and has studied through a few good books.

You are thinking about it wrong. What the coach does is get you where you're going faster than if you did it without it, and certainly can add a couple of stations to your chess railroad, but it all depends on you, how much time you have to spend, and how you choose to spend it on chess.

Greeting @EvilChess
That is a very good question to which I am looking for a good answer. Personally, I think it depends on the player, and his comprehensive understanding of what chess really is. Your experience is good for me given that you have read so many books on chess. Where I bring an interesting question whether this coach would be able to help you in what you lack in the game (not you personally), and what and if he teaches him one very important element of the game. And that he is missing something that the coach does not know that he does not know, for example, what builds on what he has learned. Therefore, the student in question will not master the essence of what he has learned (be it opening, exchange, ending, etc.). And another question, which interests me personally.How much I would have progressed, considering that I had never even read books about chess about chess, and where I had improved by playing with myself, and with the chess hustlers in the park.

@PLAY5000 Perhaps the amount of knowledge you can learn from a given coach is mostly about the gap between his chess expertise and yours, which is a permanent improvement. Plus some extra points for the coach helping you to get in your best shape and motivating you, which a temporary improvement.