There are three numbers: 3, 5 and 10. Add another number and the proportion is ()

There are three numbers: 3, 5 and 10. Add another number and the proportion is ()

Add 6 (Interchange not included)
5:10=3:6
6:3=10:5
Is the score OK?
3:10=5:(50\3)
10:3=(50\3):5