3. CPI (Consumer Price Index) data is gathered by sampling prices and using a set of goods as weights. These sets would be renewed every few years.

4. There are 2 types of data needed to complete the CPI; price system & weighting system. The weighting system are estimates of the shares of the different types of expenditure. It is necessary because it is needed to complete the CPI, if it didn’t exist then we wouldn’t have a CPI in the first place.

5. My opinion- To me, I think that CPI definitely has its use, but its not exactly exact. I think it overestimates the inflation level. For example, housing and energy costs are their real costs, whereas the housing market just consistently changes.

6. These sets would be renewed every few years. In some countries CPI is measured monthly, while in other countries they are measured quarterly.

7. According to many other websites, before CPI there was PPI, Producer Price Index. It’s a group of indexes that measures the average change in selling prices received by domestic producers of goods and services. It measures price change from the perspective of the seller.

8. 1- Sydney 2- Melbourne 3- Perth 4- Canberra 5- Brisbane 6- Adelaide 7- Hobart