This video tutorial is in the Education category which will show you how to calculate standard deviation with TI graphing calculator. First you got to enter the data in to the calculator. Go to stat and click on enter. This will edit a list. Now you type in these numbers: 50, 20, 33, 40 and 55. Then press stat and click on enter. This will bring up the 1-var stats page. Press the "2nd" button and L1, because all our data is in L1. Click on enter and you will get all the data that you will need. The standard deviation is the figure at the bottom of the screen.