If the mpc is 0.70 and investment increases by $3 billion, the equilibrium gdp will

If the MPC is 0.70 and investment increases by $3 billion, the equilibrium GDP will increase by $10 billion. 

The GDP is the Gross Domestic Product and the MPC is the marginal propensity to consume. The MPC tracks that a raise in pay will increase consumers spending on goods and services. If there is an increase in spending budget, then the GDP will increase because of more spending power.

The federal reserve took an expansionary approach during the crisis. this was done by expanding the money supply and boosting liquidity. this can be seen in the fed's actions of lending to banks, purchasing securities, and lowering the federal funds rate in order to lower overall interest rates. the fed's goal was to increase consumer spending and overall liquidity within the system, and they pursued this by expanding the supply of liquid money.