def is_prima_facie(c_and_e, c_true, e_true, events):
    """
    Determines whether c is a prima facie cause of e.

    Parameters:
        c_and_e:    number of times both events were true in a time window
        c_true:     number of times the cause was true in a time window
        e_true:     number of times the effect was true in a window
        events:     the total number of events
    
    Returns:
        boolean
    """
    if c_true == 0:
        return(False)
    
    result = c_and_e / c_true > e_true / events
    return(result)