Consider an economy described as follows: Y=C+I+G C=200+0.75(YT) 1:5010;- Assume that G and Tare constants. r is the real interest rate. 1. (10 points) Identify endogenous and exogenous variables in the model. 2. (15 points) If government spending decreases by 50. calculate the change in private saving. public saving, and national saving. (Your answers should be numbers). 3. (15 points) If taxes decrease by 200, mlculate the change in private saving, public saving, and national saving. (Your answers should be numbers)