def closest_to_canonical(mixture_normals, canonical_mu):
    """Find the normal distribution closet to canonical mu"""
    min_index = 0
    min_distance = 1000
    for i in range(len(mixture_normals)):
        mu = mixture_normals[i][0]
        distance = abs(mu - canonical_mu)
        if distance < min_distance:
            min_index = i
            min_distance = distance

    match = mixture_normals.pop(min_index)
    return match, mixture_normals, min_distance