1. **State the problem:** Determine if the given relation is a function. 2. **Recall the definition of a function:** A relation is a function if every input (x-value) corresponds to exactly one output (y-value). 3. **Analyze the given data:** The x-values are 9, 3, 5, and 10. The corresponding y-values are 8, 1, 15, and -13. 4. **Check for repeated x-values:** Each x-value appears only once, so each input has a unique output. 5. **Conclusion:** Since no x-value is repeated with different y-values, this relation is a function. **Final answer:** Yes, this relation is a function.