def find_mean(data):
    """
    Find mean of all elements of a given list

    Parameters
    ----------
    data : list
        List of data. Elements are numbers

    Returns
    -------
    float : float
        Mean of list
    """
    # Check that the input list has numbers
    for n in data:
        assert type(n) == int or type(n) == float

    return sum(data) / len(data)