Given:
ΔY = $5,000, the change in income
ΔS = 50,000 - 54,000 = - 4,000, the change in savings.
By definition,
MPS (Marginal Propensity to Spend) is
MPS = ΔS/ΔY = -4000/5000 = -0.8
The relation between MPS and MPC (Marginal Propensity to Consume) is
MPS + MPC = 1.
Therefore
MPC - 0.8 = 1
MPC = 1.8
Answer:
MPS = 0.8
MPC = 1.8