There are two ways to calculate a conditional average in Excel, both involve some logic and some special functions.

Excel doesn't have a built-in AVERAGEIF() function, but you can still average values, conditionally.

Calculate the weighted average of interest rates in Microsoft Excel to compute the most accurate average interest rate among a group of lenders who received different rates. When you take a ...

Microsoft Excel 2010 provides a formula for calculating the average value from multiple worksheets in a workbook. Before you apply this formula, check that each worksheet is formatted the same way ...

With Excel and data from your broker, however, calculating the average return is fairly easy using the XIRR function. How to calculate average stock returns in Excel ...

This makes Excel By Example invaluable because it addresses its topics in a step-by-step, example format that allows readers to immediately make use of the ideas introduced by Kagan.