from typing import List
def mean_absolute_deviation(numbers: List[float]) -> float:
    mean = sum(numbers) / len(numbers)
    return sum(abs(x - mean) for x in numbers) / len(numbers)
from typing import List
def intersperse(numbers: List[int], delimeter: int) -> List[int]:
    if not numbers:
        return []
    result = []
    for n in numbers[:-1]:
        result.append(n)
        result.append(delimeter)
    result.append(numbers[-1])
    return result