Elasticity Formula Calculations: Edexcel IAL Economics

Knowledge 1, Application 3
Quantitative skills assessed:
QS2 Calculate, use and understand percentages, percentage
changes and percentage point changes
QS8: Make calculations of elasticity and interpret the result.
QS9: Interpret, apply and analyse information in written, graphical, tabular and numerical forms
Knowledge
1 mark for definition/the formula income elasticity of demand
\% change in quantity demanded
(1)
\% change in income
Application
Up to 3 marks for calculations:
- Change in quantity of car sales
23.56 m-21.52 m=2.04
Change in quantity ÷ original quantity $\times 100$$2.04 m \div 21.52 m \times 100=9.48 \%(\mathbf{1}) 9.4795539033$
- Change in income
114029-106837=7192
Change in income $\div$ original income $\times 100$$7192 \div 106837 \times 100=6.73 \%(\mathbf{1}) \mathbf{6. 7 3 1 7 5 0 2 3 6 3}$$$\begin{aligned} 9.48 \div 6.73 =+1.41(1) \end{aligned}$$
Accept reasonable rounding e.g.
$$\begin{aligned} 9.5 \div 6.7 =+1.42 \end{aligned}$$
NB: if correct answer (e.g. 1.41, 1.409, 1.4086, 1.408,
1.408186, 1.42) is given, award full marks regardless of
working.
Accept reasonable rounding from full calculation
If 1.41% or -1.41 is given award 3 marks