"Where you finished" would be "dove hai finito". "Sei finito" alone would mean "you're finished", but when put next to a place like the "dove", it becomes "to end up", i.e. you got lost and ended up in some unforeseen place. That's probably why the "went" option. I don't see anything wrong with "guess" or "assume" for supporre, the implied meaning is very close.
">>Sei finito" alone would mean "you're finished", but when put next to a place like the "dove", it becomes "to end up"," But don't "where you ended up"/ "where you finished" mean pretty much the same in general English mr ant? I'm northern Brit and I can well imagine someone saying either of these English phrases to express lack of surprise at an outcome, with a fair sense that it was bad.
I put "I can imagine where you finished" and was marked down but to be honest still can't figure out why.
I'm not familiar with that usage, but most occurrences I find are related to race results or chart positions; the Italian is more general, and could apply just as well to a tourist ending up in the wrong town or an investigator following the leads to an unexpected place. I suspect that marking that translation wrong has the merit of alerting students to the difference, but as I said I'm not sure how much the meanings differ.