Using it's concept, the standard deviation for the given data-set is of 8.22.
The mean for this problem is:
M = (17 + 26 + 28 + 9 + 30 + 29 + 6 + 21 + 23)/9 = 21
Hence the standard deviation is:
[tex]S = \sqrt{\frac{(17-21)^2 + (26-21)^2 + (28-21)^2 + \cdots + (21-21)^2 + (23-21)^2}{9}} = 8.22[/tex]
More can be learned about the standard deviation of a data-set at https://brainly.com/question/12180602
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