【正确答案】

【答案解析】percentage change in quantity =(4-3)/[(4+3)/21=0.286=28.6% percentage change in price =(2-2.5)/[(2+2.5)/2]=-0.222=-22.2% 28.6%/-22.2%=-1.29 Since the price elasticity of demand is greater than 1 ( ignore the sign) , product Z is elastic.