noun
ballpark
BAWL-pahrk/ˈbɔːlpɑːrk/
An approximate range within which a value or estimate falls.
The shaded range puts the estimate in the ballpark of 100 to 150.

Etymology
A baseball stadium became an image for being within a broad acceptable range.
More examples
- We need a figure in the right ballpark before planning the project.
- Her guess is in the ballpark, though the exact cost is higher.
Forms
ballpark · ballparks · ballparked · ballparking