Excel has several add-ins that are useful in a business environment. An Excel add-in is a file/workbook (usually with an extension.xlas in Excel 2010 and 2007 or.xla with earlier versions) that can be activated when you open Excel. The file contains VBA code (macro) that adds more features to Excel; usually it is in the form of new functions.
Add-ins provide an excellent way of increasing the power of Excel and they are the ideal vehicle for distributing your custom functions or procedures. Excel is shipped with a variety of add-ins ready for you to load and start using, and many third-party add-ins are available to download from a variety of sites.
One of the pre-programmed add-ins in Excel is called Data Analysis (called Analysis ToolPak before installation and/or activation). The ToolPak contains a variety of statistical functions—I will demonstrate a couple of them here.
First, check to see if the Analysis ToolPak is activated in your Excel. Look for on the right side of the Data ribbon. If it is not there, you will need to activate it. In previous Excel versions, it is the last item in the Tools menu.
First things first: If you have to install the Analysis ToolPak, follow these steps: