def mean_hr_bpm(num_beats, duration):
    """Average heart rate calculation

    This is a simple function that converts seconds to minutes and divides
    the total number of beats found by the total minutes in the strip.

    :param num_beats: a single integer of the number of total beats in a strip
    :param duration: a single float for the time duration of the strip

    :returns: a single float of the average heart rate in the strip
    """
    minutes = duration/60
    mean_hr_bpm = num_beats/minutes
    return mean_hr_bpm