Leo: Premise: "An older white man in a black cowboy hat sings into a microphone."
Hypothesis: "He is at a karaoke bar."
Do we know that the hypothesis entailed by the premise?
Mei: OK, So, let's think first...
Me:
A Karaoke bar is not the only place where a man might sing into a microphone.
Thus, the answer is it is not possible to tell.