Assume the following unctions are for the goods market of a hypothetical economy: {1) I = 150- lr; {2) C=T+.8'r'd {3) T=50+0.25Y {4) G=13||Il Note: '1' is income and r is the interest rate a) Derive the IS curve for this economy. 1:) Use appropriate scale to sketch the IS curve is part (a) above. c) Determine and interpret the slope of the IS curve in part a) above. d} Explain how a change in each of the following will affect the IS curve in part a) above: i) A balance budget increase in government expenditure of 61] units. ii} An increase autonomous consumption to 800 units iii) An increase in the interest sensitivity of investment to 20. iv) An increase in the marginal propensity to save to .025. v) A decrease in the marginal tax rate to 0.15