Yes! This is looking to see whether you can make reasonable assumptions/estimates.
To me, the key here tends to be in the product features.
With these types of cases, you often receive information on how your features stack up against the competition (and possibly information on customer preferences).
You need to basically say "ok, how much better is my product compared to competition?" You also need to consider how many competitors there are.
So, if there are six competitors and your product is average, you can assume ~16% market share. However, if your product is #1, then you could get between twice and much and 50% of the market share (i.e. 32-50%).
^This is just an example, but if you provide us the numbers we can help you come up with reasonable #s (and, most importantly, talk through the reasoning)