def aad(values, mean):
    return sum(value - mean for value in values) / len(values)


def mad(values, mean):
    ad = []
    for _, value in enumerate(values):
        ad.append(value - mean)
    return np.median(ad)


def iqr(values):
    q75, q25 = np.percentile(values, [75 ,25])
    return q75 - q25