code: def on_select_mean_fit_box(self, event):
          
          new_mean_fit = self.mean_fit_box.GetValue()
          self.parent.mean_fit_box.SetStringSelection(new_mean_fit)
          self.parent.onSelect_mean_fit_box(event)
docs: set parent Zeq_GUI to reflect the change in this box then replot the high level means plot
          @param: event -> the wx.COMBOBOXEVENT that triggered this function