Final answer:
The long-run equilibrium price level cannot be determined based on the given information.
Step-by-step explanation:
The long-run aggregate supply curve represents the level of real GDP in base year dollars.
In this case, the question states that the long-run aggregate supply curve is positioned at a real GDP level of $ trillion in base year dollars. The question specifically asks for the long-run equilibrium price level in index number form.
However, there is no information provided in the given references that relates to the specific price level at the given real GDP level. Therefore, we cannot determine the long-run equilibrium price level based on the given information.