If the average of a set of data 2, 4, x, 6, 8 is 6, then the standard deviation of this set of data is () A. 10B. 8C. 6D. 22

From the meaning of the question: x = 30 - (2 + 4 + 6 + 8) = 10, variance S2 = 15 [(2-6) 2 + (4-6) 2 + (10-6) 2 + (6-6) 2 + (8-6) 2] = 8, so the standard deviation of the five data is s = S2 = 22, so D

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