Answer:
We need to calculate quantity demanded of good X
Qxd = 10,000 − 4PX + 5PY + 2M +
AX
Qxd = 10,000 − 4(50) + 5(100) + 2(25000) + 1000
Qxd = 10,000 - 200 + 500 + 50000 + 1000
Qxd = 61,300
a. E(P) = ∆Qx/∆Px * (Px / Qx)
E(P) = - 4 * (50 / 61,300)
{where, ∆Qx/∆Px is the price coefficient = -4}
E(P) = = - 0.003 (The absolute value is 0.003)
Demand is inelastic, because price elasticity is less than 1.
b. CPED = ∆Qx/∆Py * (Py / Qx)
CPED = 5 * (100 / 61,300)
[where, ∆Qx/∆Py is the price coefficient of good Y = 5]
CPED = 0.008
c. IED = ∆Qx/∆M * (M / Qx)
= 2 * (25,000 / 61,300)
[where, ∆Qx/∆M is the income coefficient = 2]
= 0.816
d. Good Y and X is subtitles because CPED is positive.
e. Good X is a normal good because income elasticity is positive.
