StatCrunch Instructions: Standard Deviation
  To open the file (sdintuition.xls) in StatCrunch you must first  right-click here and choose "Save Target As" to  download the file to your computer. Next click here  to open StatCrunch in a separate window and login using your  username and password.
    - Click on the link "Open StatCrunch" at the top of the My  StatCrunch page. 
- To open the data set, click on the Data button in the top  row and select Load -> From file -> on my computer.
- Under File, press the Browse button and select the data set  you downloaded.
- Scroll to the bottom of the page and click on "Load  File."
To ask StatCrunch for the descriptive statistics of the three  distributions:
    - Choose Stat -> Summary Stats -> Columns
- In the Summary Stats window select the columns: Class I,  Class II and Class III
- Press Compute!