Point Elasticity of Price demand
PointElasticity of Price of demand takes the elasticity of a particularspot on a curve or at times between the points. It is given by:
%Δ Q / Q
%Δ P / P
%Δ Q/Q= 5/50*100
%Δ P/P = 13/70*100
Arc Price Elasticity of demand
Thisis a measure of elasticity between any to specific points or spots ona curve.
Mid-pointof 70 and 63 is 66.5
%Δ in quantity= 13/66.5= 0.19548872
%Δ in price= 5/52.5= -0.0952381
ThereforePED = 0.19548872/-.0952381
ArcPrice Elasticity of demand = -2.0526
Arc price elasticity of supply
%Δ in quantity= 30/55=0.5454
%Δ in price =10/45=0.2222
Arcprice elasticity of supply= 2.4545
Income Elasticity of Demand
Itmeasures the degree of change of demand of a good or service as aresult of changes in income.
YED=%change in Q.D           % change in Income
%change in QD= (3/12)* 100 = 25%
%change in Income= (10,000/25,000)*100 =25%
Inthis case, there is there is unitary income elasticity of demandgiven that an increase in income is results in the same proportionateincrease in the quantity of goods demanded.
(12+15/25+20)*5/3= (27/45)*5/3= 0.6*1.6667=1
Theyare substitute goods because price elasticity is positive as we get(1) from the calculations.