Answer:
2
Step-by-step explanation:
Basically you don't need to find x to know the scale factor ,
but I did.So you see that multiple 3 by 2 you will get 6
(MN) and the same will happen with 5.5 and NO (which is 11 btw).
so you can write 2:1
From 5 miles to 16 miles in 11 miles in between.
1 and 3 they share a relationship of +2, 3 and 6 share x2, 5 and 8 share +3, 7 and 21 share x3
If you finish the question I may be able to answer it. ^^