$200 180 160 140 120 100 80 60 40 20 Aggregate Expenditures (Billions) 0 $20 40 60 80 100 120 140160 180 200 Real GDP (Billions) Refer to the diagram for a private closed economy. In this economy. investment Multiple Choice 0 decreases as GDP increases. 0 increases as GDP increases. O is $40 billion at all levels of GDP. 0 is $60 billion at all levels of GDP