Keyword Analysis & Research: what is the symbol for standard deviation

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what is the symbol for standard deviation	1.5	0.2	5057	18	41
what	1	0.9	176	78	4
is	1.3	0.8	105	3	2
the	0.18	0.7	9251	32	3
symbol	0.95	0.3	843	25	6
for	0.07	0.4	8542	58	3
standard	1.34	0.6	7851	23	8
deviation	1.08	1	4708	42	9

Keyword	CPC	PCC	Volume	Score
what is the symbol for standard deviation	0.07	0.5	464	7