Answer:
The answer to your question is 490 visitors
Step-by-step explanation:
Data
3/14 from North america
5/12 from Europe
Visitors from North america = 252
Process
1.- To solve this problem use proportions and cross multiplication
          3/14 ---------------------- 252 visitors
          5/12 ----------------------  x
          x = (5/12 x 252) / 3/14
-Simplify
          x = 1260/12 / 3/14
          x = 105 / 3/14
          x = 490 visitors
2.- Conclusion
490 visitors were from Europe