"make some guesses" is correct and usable in written English.
You could use this phrase to ask someone to guess the answer to a question or give their opinion. For example: "In the comments below, make some guesses as to which celebrity will be the next guest on the show."
Duckworth could make some guesses.
Hilton management decided that it needed to make some guesses about the economy, even if they proved wrong.
Incidentally, if you assume that the Republican contest will continue to go back-and-forth and make some guesses about how each state will vote, you wind up with a lot of scenarios like this one.
On the basis of the few reliable quantitative studies (mostly conducted in courts), we can make some guesses as to when mediation might be effective, at least for commercial/business disputes.
You can make some guesses about why this might be the case with poverty being at the lead of the list, but there are other issues that come into play as well that help drive this relationship.
"We have been struggling all weekend, and we had to make some guesses as to what kind of set-up we wanted and it seemed to work OK.
It makes some guesses automatically, and records other guesses made by the user.
Referring to Microsoft as "they," instead of "we," Mr. Blackley discussed the different sizes of Xbox controllers for Japan and North America, made some guesses about Sony's plans for online games and apologized for E3.
Cost comparisons are difficult because the 60 GHz transceivers are not yet commercially available for data centers, but by making some guesses, the researchers suggest that the cost of wireless connectivity could be as low as 1/12 that of conventional switches and wires for a hypothetical data center with 10,000 servers.
"The War That Made America," a four-part edutainment series that begins tonight on PBS, makes some guesses about that and hundreds of other lost historical details, as it chronicles the French and Indian War in high-gloss and ultimately successful re-creations.
