Question

The A. M. of n observation is $\overline{x}.$ If the sum of n-4 observations is K, then the mean of remaining observations is

• A. $\frac{\overline{x}-K}{4}$
• B. $\frac{n\overline{x}-K}{n-4}$
• C. $\frac{n\overline{x}-K}{4}$
• D. $\frac{n\overline{x}-(n-4)K}{4}$

Answer 1

The correct option is C $\frac{n\overline{x}-K}{4}$

Sum of $n$ observations $=n\overline{x}$
Sum of $(n-4)$ observations $=k$
$\therefore$ Sum of remaining 4 observations $=n\overline{x}-k$
Hence required
mean $=\frac{n\overline{x}-k}{4}$