def triples_sum_to_zero(l: list):
    for i in range(len(l)):
        for j in range(i + 1, len(l)):
            for k in range(j + 1, len(l)):
                if l[i] + l[j] + l[k] == 0:
                    return True
    return False
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)