Do animes help make the mangas that they are based off more successful?

Naturally

if the anime is popular

more people will take interest in the manga

(especially while the anime is still running and the manga is "ahead" of the anime).

This also is the case if the anime stops. Fans of the anime who do not purchase the manga are more likely to buy the manga to see how the story ends.

I don't know if a poorly-made anime affects manga sales since - typically - anime is based on already-popular manga. I would expect a poorly-made anime would incense fans of the manga, but they would still be fans of the manga. Naturally a poorly-made anime is not likely to create new fans of that manga.

yes

That's the whole point of why most anime are made in the first place. Even a poorly made anime can still attract attention to the source material, if only to see what the story was supposed to be. And anime are hardly ever intended to tell the whole story as they are far more expensive to make and moreover, the boost in popularity requires that the manga still be in print, otherwise there'd be nothing to sell. Most anime are just over-blown commercials.

Well, yeah. Because it'll receive more exposure than before, which makes people that never heard of the title, or wanted to know the continuation, checks the manga/LN version.

And if the anime does a poor adaptation and very different from the manga/LN, the people who knows it usually recommends others to read it instead. This happened in several titles in the past, and one of them was the Magister Negi Magi series.

The first anime was such a trainwreck, and the second one was completely unrelated and more of a Shaft gag anime. People who interested in the series, but hated the anime, opted to read the much better manga version instead. And due to that, the series managed to produced several short OAVs that was faithful to the story, as a special bonus for the manga version.