Plausible means believable or credible, as in "It is plausible to assume the US will remain in a recession for the rest of this year."
The youth's answer, though not quite correct, was plausible
We considered Detective Martin's theory, but in the end it was just not plausible. The weather report indicated that a severe tornado was highly plausible for a neighboring county.
He had a plausible answer but in the end it was wrong.
Stanley did not think that Spencer's explanation seemed plausible.