Mean and variance of six observations are 6 and 12 respectively. If each observation is multiplied by 3 ,…
Mean and variance of six observations are 6 and 12 respectively. If each observation is multiplied by 3 , then new variance of the resulting observations is
288
36
18
108
Solution
When each item of a data is multiplied by $\lambda$, Variance is multiplied by $\lambda^2$.
$\begin{aligned}
\therefore \quad \text { New variance } & =3^2 \times 12 \\
& =9 \times 12 \\
& =108
\end{aligned}$