Keyword Analysis & Research: what does sigma represent in math

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what does sigma represent in math	0.23	0.6	1704	88	33
what	0.47	1	5089	86	4
does	0.42	0.2	853	38	4
sigma	0.77	0.2	8266	85	5
represent	1.25	0.8	3648	83	9
in	0.54	0.5	7922	11	2
math	0.79	0.9	7069	45	4

Keyword	CPC	PCC	Volume	Score
what does sigma represent in math	0.05	0.3	719	33