Suppose that the aggregate expenditure curve can be expressed algebraically as
![](https://test.transtutors.com/qimg/496e78ab-2e6f-4a7c-91f1-b0aec375458f.png)
Where AE is aggregate expenditures and r is the real interest rate expressed as a decimal. You check the website of the Congressional Budget Office and learn that the level of potential output is 2,900. What is the long-run real interest rate?