Answer: $200 billion
Step-by-step explanation:
First find the government spending multiplier:
Multiplier = 1 / (1 - MPC)
= 1 / (1 - 0.8)
= 5
The government wants to increase the real GDP to $19 trillion from $18 trillion which means that they want to increase it by $1 trillion.
In order to increase it by $1 trillion, the amount the government needs to spend is:
Increase in real GDP = Multiplier * Government spending
1 trillion = 5 * Government spending
Government spending = 1 trillion / 5
= $200 billion