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.
A sigma is a symbol used in statistics for a standard deviation. A standard deviation is the measure of a spread of a distribution of some quantities. For example, if you have a group of boys and measure their heights, there will be some tall boys and some short boys. There will also be some medium height boys.