The sum of squares of 50 data is 800, and the average is 3. Find the standard deviation of the 50 data

Variance = ∑ (flag value average) ^ 2 △ 50 = | ∑ flag value ^ 2-2 * average * ∑ flag value + ∑ average ^ 2 | △ 50 = | 800-2 * 3 * 150 + 3 * 3 * 50 | △ 50 = 7
Standard deviation = root sign variance ≈ 2.64575

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