The marginal propensity to consume is

Multiplier effect is an effect in economics, in which an increase in spending produces an increase in national income and consumption greater than the initial amount spent. If MPS =...

induced consumption expenditure = 0.9*Income

marginal propensity to consume = (consumption spending2 - consumption spending1)/( income2 – income1) = ($13.5 - $12) / ($15-$13) = 0.75

MPC or Marginal propensity to consume is also given as, (1-MPS).  Where, MPS is marginal propensity to save.So, if MPS =3/4Then MPC = (1-3/4)                 = 1/4 or 0.25

Y=C+IC=a+cYY=200+0.75Y+6000.25Y=800Y=3200Since this answer doesn't exist, I've decided that it is 8000

(4) 4If MPC = 3/4 or 0.75, multiplier is=1/(1-0.75) = 1/0.25 = 100/25 = 4

A change in government spending that can eliminate the gap identified should be equal to the taxation offered to private sector

The other factor is that influences a households induced consumption is its disposable income, or the greater the level of income. A community's ability yo consume increases with the increase...

largeBased on the aggregate expenditures model, government spending or investment tend to the income of consumers, hence they will spend more.

(4) 1/4