@Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_cost_graph);
    parentTabbedActivity = (TabbedOutputActivity) getParent();
    calculatorList = parentTabbedActivity.getCalculators();

    GraphicalView savingsChart =
        ChartFactory.getLineChartView(this, getCostsDataset(), getCostsRenderer());
    setContentView(savingsChart);
  }
 @Override
 public void onResume() {
   super.onResume();
   parentTabbedActivity.setTabId(TabbedOutputActivity.COST_GRAPH_ID);
 }
 @Override
 public void onBackPressed() {
   parentTabbedActivity.onBackPressed();
 }