JEE Mains · Maths · STD 11 - 13. statistics
Let \(a_1, a_2, \ldots . a_{10}\) be \(10\) observations such that \(\sum_{\mathrm{k}=1}^{10} \mathrm{a}_{\mathrm{k}}=50\) and \(\sum_{\forall \mathrm{k}<\mathrm{j}} \mathrm{a}_{\mathrm{k}} \cdot \mathrm{a}_{\mathrm{j}}=1100\). Then the standard deviation of \(a_1, a_2, \ldots, a_{10}\) is equal to :
- A \(5\)
- B \(\sqrt{5}\)
- C \(10\)
- D \(\sqrt{115}\)
Answer & Solution
Correct Answer
(B) \(\sqrt{5}\)
Step-by-step Solution
Detailed explanation
\( \sum_{\mathrm{k}=1}^{10} \mathrm{a}_{\mathrm{k}}=50 \) \( \mathrm{a}_1+\mathrm{a}_2+\ldots+\mathrm{a}_{10}=50\) \(.........(i)\) \( \sum_{\forall \mathrm{k}<\mathrm{j}} \mathrm{a}_{\mathrm{k}} \mathrm{a}_{\mathrm{j}}=1100 \) \(...........(ii)\)…
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