def forward_prop_affine_transform(a_prev, weight, bias):
    """
    Apply affine transformation for forward prop

    Parameters
    ----------
    a_prev: ndarray
        Previous layer's activation
    weight: ndarray
        Weight
    bias: ndarray
        Bias

    Returns
    -------
    z: ndarray
        Affine transform
    """

    return a_prev.dot(weight) + bias