MathematicsMedium89×since 2002Q5421In a series of 2n observations, half of them equal aaa and remaining half equal –a–a–a. If the standard deviation of the observations is 2, then ∣a∣|a|∣a∣ equalsA2B2\sqrt 22C1n{1 \over n}n1D2n{{\sqrt 2 } \over n}n2Check answerSkip