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JEE Mains · Maths · STD 11 - 13. statistics

Let the mean of 6 observation \(1,2,4,5, x\) and \(y\) be \(5\) and their variance be \(10\) . Then their mean deviation about the mean is equal to \(........\).

  1. A \(\frac{10}{3}\)
  2. B \(\frac{7}{3}\)
  3. C \(3\)
  4. D \(\frac{8}{3}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\frac{8}{3}\)

Step-by-step Solution

Detailed explanation

\(x+y=18\{\because\) mean \(=5\}\) \(10=\frac{1+4+16+25+ x ^2+ y ^2}{6}-25\) \(x ^2+ y ^2=164 \ldots \ldots \text { (ii) }\) By solving \((i)\) and \((ii)\) \(x =8, y =10\) \(\text { M.D. }(\overline{ x })=\frac{\sum\left| x _{ i }-\overline{ x }\right|}{6}=\frac{8}{3}\)