Old Hollywood: Lewis sensationally revealed in her 1994 memoir that she was conceived in 1935 when Loretta Young, 22, and the married Clark Gable, 34, were shooting The Call of the Wild. Secret: Loretta Young is pictured with Judy Lewis in 1944, who did not know for years who her father was.
The sigma symbol provides the character used to denote the sum of an equation in mathematics. You can create a sigma sign by accessing the Character Palette, using a keyboard shortcut or by using the Special Characters menu in your current application.
So what people like to do is talk in terms of standard deviation, which is just the square root of the variance, or the square root of sigma squared. And the symbol for the standard deviation is just sigma. So now that we've figured out the variance, it's very easy to figure out the standard deviation of both of these characters. The standard deviation of this first one up here, of this first data set, is going to be the square root of 200.