Four friends are sitting in a row facing North. Sam is to the right of Tom. Amy is to the left of Tom but not next to him. Rick is between Amy and Tom. Who is sitting at the far right?

Let's decipher the arrangement conditions step by step from left to right:
1. "Sam is to the right of Tom" $⟹\text{Tom}\dots \text{Sam}$
2. "Amy is to the left of Tom but not next to him" $⟹$ There must be at least one person between Amy and Tom.
3. "Rick is between Amy and Tom" $⟹$ The arrangement becomes: $\text{Amy}-\text{Rick}-\text{Tom}$.

Combining all positions from left to right:

$$\text{Amy}\to \text{Rick}\to \text{Tom}\to \text{Sam}$$

Looking at the final order, Sam is positioned at the far right end of the row.