Question

The mean of $10$ observations is $16.3$. By an error one observation id is registered as $32$ instead of $23$. Then, the correct mean is

• A. $15.6$
• B. $15.4$
• C. $15.7$
• D. $15.8$

Answer 1

The correct option is B $15.4$

The mean of $10$ observations is $16.3$.

By error, one observation id got registered as $32$ instead of $23$

$16.3=\frac{x_1+x_2+...x_{10}}{10}$

$x_1+x_2+...x_{10}=163$

Let $\lambda =-32+23+x_1+x_2+...x_{10}$

$\lambda =-9+163$

$\lambda =154$

So, required mean is $\frac{154}{10}=15.4$