Question

The mean and variance of $7$ observations are $8$ and $16$.
If $5$ of these are $2,4,10,12,14$, find the sum of two remaining observations.

• A. $22$
• B. $13$
• C. $18$
• D. $14$

Answer 1

Answer: (D)

$14$

Let the two unknown observations be $x$ and $y$.
Mean, $u=8$.
$\Rightarrow u=8=\frac{2+4+10+12+14+x+y}{7}$
$\Rightarrow 42+x+y=56$
$\therefore x+y=14$
Ans-Option $D$