code: def CI_calc(mean, SE, CV=1.96):
      
      try:
          CI_down = mean - CV * SE
          CI_up = mean + CV * SE
          return (CI_down, CI_up)
      except Exception:
          return ("None", "None")
docs: Calculate confidence interval.
  
      :param mean: mean of data
      :type mean : float
      :param SE: standard error of data
      :type SE : float
      :param CV: critical value
      :type CV:float
      :return: confidence interval as tuple