def convert_mixing_names_to_positions(mixing_names, ind_var_names):
    """
    Parameters
    ----------
    mixing_names : list of strings.
        Denotes the names of the index variables that are being treated as
        random variables.
    ind_var_names : list of strings.
        Each string should represent (in order) the variables in the index.

    Returns
    -------
    list. All elements should be ints. Elements will be the position in
        `ind_var_names` of each of the elements in `mixing_names`.
    """
    return [ind_var_names.index(name) for name in mixing_names]