Add CI pipeline for variant 5

ci_lab/math_tools.py

@@ -0,0 +1,19 @@
+"""Mathematical helper functions."""
+
+def average(numbers: list[float]) -> float:
+    if not numbers:
+        raise ValueError("numbers must not be empty")
+    return sum(numbers) / len(numbers)
+
+def median(numbers: list[float]) -> float:
+    if not numbers:
+        raise ValueError("numbers must not be empty")
+    sorted_numbers = sorted(numbers)
+    length = len(sorted_numbers)
+    middle = length // 2
+    if length % 2 == 1:
+        return sorted_numbers[middle]
+    return (sorted_numbers[middle - 1] + sorted_numbers[middle]) / 2
+
+def is_even(number: int) -> bool:
+    return number % 2 == 0