State about the prices - Price level

Prices are of great significance in macroeconomics as indeed they are in microeconomics. Though, in microeconomics we are more interested in prices of individual services and goods and such prices are rarely significant for economy as a whole even though there are exceptions (for instance, the price of oil). In macroeconomics we are more interested in how prices change on average. We describe the price level as a weighted average of various different prices.

If p1 is price of gasoline and p2 the price of oil, then 10p1+ p2 is a price level. It is a weighted average of two prices with weights 10 and 1. Generally, price level is defined using many more prices.