Premise: "A woman in a blue sports outfit is about to hit a tennis ball."\nHypothesis: "A woman wearing a blue sports outfit is playing tennis."\nDo we know that the hypothesis entailed by the premise?
Step-by-step reasoning process below:
it is not possible to tell
She does not necessarily have to be playing tennis while she hits a tennis ball.

.

So, the answer is it is not possible to tell