For the following variables, determine whether \( r \) is a function of \( s, s \) is a function of \( r \), or neither. \( r \) is the circumference of any coin and \( s \) is its year of minting.

To determine the relationship between \( r \) (the circumference of a coin) and \( s \) (its year of minting), let's analyze both possible scenarios: 1. **Is \( r \) a function of \( s \)?** - **Function Definition:** For \( r \) to be a function of \( s \), each year \( s \) must correspond to exactly one circumference \( r \). - **Analysis:** In reality, multiple coins can be minted in the same year with different circumferences. For example, a country might release coins of varying denominations or designs in a single year, each having a different circumference. - **Conclusion:** **\( r \) is not a function of \( s \).** 2. **Is \( s \) a function of \( r \)?** - **Function Definition:** For \( s \) to be a function of \( r \), each circumference \( r \) must correspond to exactly one year \( s \). - **Analysis:** A specific circumference can be associated with coins minted in multiple different years. Additionally, different countries might produce coins with the same circumference in different years. - **Conclusion:** **\( s \) is not a function of \( r \).** Since neither \( r \) is uniquely determined by \( s \) nor \( s \) is uniquely determined by \( r \), the relationship between them falls into the "neither" category. **Answer:** Neither variable is a function of the other.