JEE Mains · Maths · STD 11 - 13. statistics
\(5\) students of a class have an average height \(150\, cm\) and variance \(18\, cm^2\). A new student, whose height is \(156\, cm\), joined them. The variance (in \(cm^2\)) of the height of these six students is
- A \(16\)
- B \(22\)
- C \(20\)
- D \(18\)
Answer & Solution
Correct Answer
(C) \(20\)
Step-by-step Solution
Detailed explanation
Let \(5\) students are \({x_1},{x_2},{x_3},{x_4},{x_5}\) Given \(\bar x = \frac{{\sum {{x_i}} }}{5} = 150\,\,\,\, \Rightarrow \sum\limits_{i = 1}^5 { = 750\,\,\,\,\,\,.....\left( 1 \right)} \)…
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