The proposition \( (P \rightarrow Q) \rightarrow R \) is a conditional statement. In logic:
- \( P \rightarrow Q \) is true if either \( P \) is false or \( Q \) is true.
- Since \( P \) is false, the statement \( P \rightarrow Q \) is true (because a false hypothesis always makes the implication true).
Thus, the whole expression \( (P \rightarrow Q) \rightarrow R \) depends on \( R \). Since \( (P \rightarrow Q) \) is true, the value of the proposition is equivalent to the value of \( R \).
Therefore, the value of the proposition is \( R \).