Answer :
Index:
p=original price
(130/100)=30% increase in price
(80/100)=20% decrease in price
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2003: (130/100)*p
2004: (130/100)*p*(80/100)
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Net change in price:
(130/100)*p*(80/100)-p
=p((130/100)*(80/100)-1)
=p*(1/25)
p=original price
(130/100)=30% increase in price
(80/100)=20% decrease in price
------------------------------------------
2003: (130/100)*p
2004: (130/100)*p*(80/100)
------------------------------------------
Net change in price:
(130/100)*p*(80/100)-p
=p((130/100)*(80/100)-1)
=p*(1/25)