Part of my Business Data Analysis (Statistics) class is to cover Student's t-Test. This is a test to figure out if there is a difference statistically between two samples. Excel has the "Analysis Toolpak" Add-In that can do the donkey work for you, though curiously it is not available by default and must be switched on. It took me a while to get the video right for this as there are quite a few different ways of doing the same thing.
In the video below I compare the means of two samples and determine that there is a difference statistically between them. The video was recorded using Snagit.