The average prices of four commodities are given in the following table:
![](https://test.transtutors.com/qimg/fdac0d7c-74a6-4d91-9d30-c740bc97e6d6.png)
The number of units used annually by a certain company is approximately 400, 200, 600 and 100 for the commodities A, B, C and D respectively. Calculate a weighted price index for Years 1 and 2 using Year 0 as the base year.