Keyword Analysis & Research: why do you divide by n 1 for sample variance

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
why do you divide by n 1 for sample variance	0.39	1	9926	95	44
why	0.97	0.8	6829	28	3
do	0.99	0.2	1350	24	2
you	0.7	0.4	2172	100	3
divide	0.12	0.7	3598	54	6
by	0.36	0.3	5545	30	2
n	0.59	0.3	5910	98	1
1	1.56	0.8	219	41	1
for	0.06	0.8	8587	82	3
sample	0.16	0.6	1508	81	6
variance	1.47	0.6	1626	99	8

Keyword	CPC	PCC	Volume	Score
why do you divide by n 1 for sample variance	0.73	0.1	835	37