Question

Mean of $427$ values is $329$. A value is excluded, however the means remains same. The excluded value is

• A. $427$
• B. $329$
• C. $276$
• D. none of the above

Answer 1

Answer: (B)

$329$

Mean of 427 values is 329.

$\frac{1}{427}{\sum }_{i=1}^{427}{x}_i=329{\sum }_{i=1}^{427}{x}_i=329\ast 427=140483$

Mean of 426 values is 329.

$\frac{1}{426}{\sum }_{i=1}^{426}{x}_i=329{\sum }_{i=1}^{426}{x}_i=329\ast 426=140154$

Excluded value would be difference of sum of 427 values and sum of 426 values.

$Excludedvalue={\sum }_{i=1}^{427}Xi-{\sum }_{i=1}^{426}Xi=140483-140154=329$