The actual definition is harder to understand than simply showing an example of how to calculate weighted average. Say you simultaneously invest different amounts of money in two companies ...

To calculate the average percentage difference over time, you'll need to build a time series of data. The starting point is the price information for each date on which you're producing an average.

In order to calculate the average price that a company paid when it bought back shares, you need to know two key things. First, you'll want to know how many shares the company repurchased.

To calculate the weighted average, you need to add up the total weighted grades (16 + 6 = 22), and divide by the total weight (4 + 2 = 6). When we do this, you arrive at a GPA of 3.67, which is ...