def get_vbr_bitrate(mpeg_size, sample_count, sample_rate):
    """Get average bitrate of VBR file.
    
    :param mpeg_size: Size of MPEG in bytes.
    :type mpeg_size: number
    
    :param sample_count: Count of samples.
    :type sample_count: number

    :param sample_rate: Sample rate in Hz.
    :type sample_rate: number
    
    :return: Average bitrate in kilobits per second.
    :rtype: float
    
    """
    bytes_per_sample = float(mpeg_size) / float(sample_count)
    bytes_per_second = bytes_per_sample * float(sample_rate)
    bits_per_second = bytes_per_second * 8
    return bits_per_second / 1000
