Are "acquired for $X" statements related to reality?

We're hearing about a lot of big acquisitions these days. For instance, Lithium and Klout put out a press release that one acquired the other for $200M. But since it's some mix of cash and stock, presumably this is based on Lithium's pre-IPO valuation of itself.

These valuations could be based on reality (outside investors) or maybe they are simply pulled out of thin air, like 2-3x the last time someone invested?

Even if there is some kind of standard formula for figuring this out, is anybody checking these numbers? Given the way the tech press works, I doubt it.