Suppose a class has 7 students. The average m | vedclass

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Question

$20=\frac{\sum\limits_{ i =1}^{7}\left| x _{ i }-62\right|^{2}}{7}$

$\Rightarrow\left| x _{1}-62\right|^{2}+\left| x _{2}-62\right|^{2}+\ldots .+\l

Vedclass · Accepted Answer

$0$

Vedclass · Answer

$20=\frac{\sum\limits_{ i =1}^{7}\left| x _{ i }-62\right|^{2}}{7}$

$\Rightarrow\left| x _{1}-62\right|^{2}+\left| x _{2}-62\right|^{2}+\ldots .+\left| x _{7}-62\right|^{2}=140$

$If$ $x _{1}=49$

$|49-62|^{2}=169$

then, $\left| x _{2}-62\right|^{2}+\ldots .+\left| x _{7}-62\right|^{2}=$ Negative Number which is not possible, therefore, no student can fail.

${x_i}$	$6$	$10$	$14$	$18$	$24$	$28$	$30$
${f_i}$	$2$	$4$	$7$	$12$	$8$	$4$	$3$

Suppose a class has $7$ students. The average marks of these students in the mathematics examination is $62$, and their variance is $20$ . A student fails in the examination if $he/she$ gets less than $50$ marks, then in worst case, the number of students can fail is

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