------
## 最终结论
```python
def find_last_occurrence(arr, target):
    for i in range(len(arr) - 1, -1, -1):
        if arr[i] == target:
            return i
    return -1

# Test cases
assert find_last_occurrence([2, 5, 5, 5, 6, 6, 8, 9, 9, 9], 5) == 3
assert find_last_occurrence([2, 3, 5, 8, 6, 6, 8, 9, 9, 9], 9) == 9
assert find_last_occurrence([2, 2, 1, 5, 6, 6, 6, 9, 9, 9], 6) == 6
```