QUESTION 17 Using the following Information to answer questions 10- 18 The extended demand function of good X is: QdX = 1400 ? 20 PX - 10 PY + 0.1 M where: QdX = quantity demanded of good X ? PX = Price of good X ? M = Average consumer income PY = Price of related good Y (related in consumption to good X ) Use these prices of good Y (PY. and the quantities demanded of good X (QDX. to calculate the cross-price elasticity of the demand of good X when the price of good Y increases from 50 to 80 (and PX = 50 and M = 10,000). 0.6867 0.6867 0.8667 0.8667