Answer:
The by $10 billion would government spending have to rise to shift the aggregate demand curve rightward by $40 billion.
Step-by-step explanation:
a) Spending multiplier = 1/(1 - MPC)
= 1/(1 - 0.8)
= 5
The required shift in spending = change in GDP/spending multiplier
= $40 billion/5
= $8 billion
Therefore, The by $10 billion would government spending have to rise to shift the aggregate demand curve rightward by $40 billion.