Bluebulb Projects' The Measure of Things presents:
4,500 is about one-tenth the number of Seats in Fenway Park.
In other words, it's 0.121390 times the count of Seats in Fenway Park, and the count of Seats in Fenway Park is 8.23790 times that amount.
(2013 figures; daytime capacity) (a.k.a. The Cathedral of Boston) (Boston, Massachusetts)