Varivence of $x_1 \cdot x_2 \cdot \cdots \quad x_n=6^2$

Variane of $a x_1 a x_2, \ldots a x_n=$ ?

varience $=\sigma^2=\frac{1}{n} \sum \limits_{i=1}^r y_i\left(n_i-\bar{x}\right)^2$

If each obs is weltiplied $2 y$ a the $y_i=a x_i \quad i . e \quad x_i=\frac{1}{a} y_i$

$y_i=a x_i n$

$\therefore \bar{y}=\frac{1}{n} \sum\limits_{i=1}^n y_i=\frac{1}{n} \sum\limits_{i=1}^n a x_i=\frac{a}{n} \sum\limits_{i=1}^n x_i=a \bar{x} .$

${\left[\because \bar{x}=\frac{1}{n} \sum\limits_{i=1}^n x_i\right]}$

$(1) \Rightarrow \quad \sigma^2=\frac{1}{A} \sum_{i=1}^n\left(\frac{1}{a} y_i-\frac{1}{a} \bar{y}\right)^2$

$\Rightarrow a a^2 \sigma^2=\frac{1}{n} \sum_{i=1}^n\left(y_i-\bar{y}\right)^2$

These varieme of new obs' is $a^2 \sigma^2$