code: def get_lower_bound(self):
          
          lower_bounds = []
  
          for distribution in self.distribs.values():
              lower_bound = distribution.percent_point(distribution.mean / 10000)
              if not pd.isnull(lower_bound):
                  lower_bounds.append(lower_bound)
  
          return min(lower_bounds)
docs: Compute the lower bound to integrate cumulative density.
  
          Returns:
              float: lower bound for cumulative density integral.