code: def arithmetic_mean(confirmed_measures):
      """
      Perform the arithmetic mean aggregation on the output obtained from
      the confirmation measure module.
  
      Parameters
      ----------
      confirmed_measures : list of float
          List of calculated confirmation measure on each set in the segmented topics.
  
      Returns
      -------
      `numpy.float`
          Arithmetic mean of all the values contained in confirmation measures.
  
      Examples
      --------
      .. sourcecode:: pycon
  
          >>> from gensim.topic_coherence.aggregation import arithmetic_mean
          >>> arithmetic_mean([1.1, 2.2, 3.3, 4.4])
          2.75
  
      """
      return np.mean(confirmed_measures)
  
label_desc: Use image node_id 1 for calling a global function with example usage: arithmetic_mean(confirmed_measures) and returns: np