When you install Excel, the most commonly used functions are installed as well.

However, there are additional functions available in the Analysis ToolPak, a set of add-in tools and functions designed for data analysis. This add-in includes a number of excellent worksheet functions that become available through the Insert Function dialog box, and some sophisticated, macro-based, statistical analysis tools.

To see if you have the Analysis ToolPak installed, go to the Tools menu. If the Data Analysis command is there (you might have to double-click the menu name to expand it to its full size), then you’re good to go.

If the Data Analysis command isn’t on your Tools menu, choose Tools, Add-Ins. If Analysis ToolPak is on the list of available add-ins, select it, and then click OK to install them. If the Analysis ToolPak isn’t in the list of available add-ins, you’ll need to run Setup to install it.