code: def mean(xs):
      """Returns the mean of an iterable.
  
      Example:
  
          >>> mean([1, 4, 7, 11])
          5.75
  
      @param xs: an iterable yielding numbers.
      @return: the mean of the numbers provided by the iterable.
  
      @see: RunningMean() if you also need the variance or the standard deviation
      """
      return RunningMean(xs).mean
  
imports: import math
label_desc: Use image node_id 1 for calling a global function with example usage: mean(xs) and returns: RunningMean