In order to answer that question, we need to know the scale of the map.
Without that information, no answer is possible.
I think you have it in the first part of the question ... the part you decided
not to post.
_________________________
OK. Now that you've provided the scale of the map,
answering the question is a piece-o-cake.
Use a proportion:
(1 inch on the map) / (4 miles on the ground) = ('x' on the map) / (17 miles on the ground)
