Question

Mean of six observations is $8$. If all the observations are multiplied by $3$.
Find the new mean.

• A. $22$
• B. $24$
• C. $52$
• D. $49$

Answer 1

The correct option is B $24$

Mean, $u=8$.
So, $\frac{x_1+x_2...x_6}{6}=8$.
$\therefore x_1+x_2...x_6=48$.
Multiplying the above equation by $3$ on both the sides we get,
$3x_1+3x_2...3x_6=48\times 3$
$\therefore u^{\prime }=\frac{3x_1+3x_2....3x_6}{6}=\frac{48\times 3}{6}$
$\therefore u^{\prime }=24$
Thus, new mean, $u^{\prime }=24$.
Ans- Option $B$