Question 608181
First, we need to find the sample mean



xbar = (8+10+12+15+17+13)/6 = 75/6 = 12.5 



So the sample mean is xbar = 12.5 



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Now subtract the sample mean from EVERY data value:

8-12.5 = -4.5
10-12.5 = -2.5
12-12.5 = -0.5
15-12.5 = 2.5
17-12.5 = 4.5
13-12.5 = 0.5




So the differences are: -4.5, -2.5, -0.5, 2.5, 4.5, 0.5 



Now square each difference:

(-4.5)^2 = 20.25
(-2.5)^2 = 6.25
(-0.5)^2 = 0.25
(2.5)^2 = 6.25
(4.5)^2 = 20.25
(0.5)^2 = 0.25




Now add up each square:

20.25+6.25+0.25+6.25+20.25+0.25 = 53.5



Now divide that sum by n-1 = 6-1 = 5 to get 53.5/5 = 10.7 



So the sample variance is 10.7 



Finally, take the square root of 10.7 to get 3.27108544675923



So the sample standard deviation is 3.27108544675923