How do you calculate percentage change?

This is an economics question. PLEASE help me out if you can!!! (I'll be sure to choose a Best Answer)



2009 Prices: $2, $4, $1

2010 Prices: $2, $6, $2

Quantity: 100, 100, 200 (both years)



Question: What is the percentage change in the price of each of the 3 goods?



And: Using a method similar to the consumer price index, compute the percentage change in the overall price level.How do you calculate percentage change?
Price Change

Goods 1 Goods 2 Goods 3

0% 50% 100%



CPI Using Laspeyres index





Goods 1 Goods 2 Goods 3

Prices 2009 2 4 1

Prices 2010 2 6 2

Quantity 2009/10 100 100 200



CPI - using Laspeyrs Formula 0% 67% 50%

Average CPI 39%





CheersHow do you calculate percentage change?
The $2 product is 0% increase

The $4 product is 50% increase

The $1 product is 100$ increase



An index might be:

.25 x 0% = 0%

.25 x 50% = 12.5%

.50 x 100% = 50%

Ave price increase = 62.5%

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