The diagram to the right represents desired saving and desired investment in a domestic economy. Net factor payments are equal to 20- $5 billion and the statistical discrepancy is equal to 0. 18- S At a world real interest rate of 3%, what is the level of net exports 'NX' ? $ billion. World real interest rate (%) E :32.5 :85.0 0- 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 Desired national saving and investment (billions)