MathematicsMedium89×since 2002Q5491Let a1,a2,…a10\mathrm{a}_1, \mathrm{a}_2, \ldots \mathrm{a}_{10}a1,a2,…a10 be 10 observations such that ∑k=110ak=50\sum\limits_{\mathrm{k}=1}^{10} \mathrm{a}_{\mathrm{k}}=50k=1∑10ak=50 and ∑∀k<jak⋅aj=1100\sum\limits_{\forall \mathrm{k} < \mathrm{j}} \mathrm{a}_{\mathrm{k}} \cdot \mathrm{a}_{\mathrm{j}}=1100∀k<j∑ak⋅aj=1100. Then the standard deviation of a1,a2,…,a10\mathrm{a}_1, \mathrm{a}_2, \ldots, \mathrm{a}_{10}a1,a2,…,a10 is equal to :A5B115\sqrt{115}115C10D5\sqrt{5}5Check answerSkip