Question

Marks obtained (in mathematics) by $9$ student are given below:
$60,67,52,76,50,51,74,45$ and $56$
(a) find the arithmetic mean
(b) if marks of each student be increased by $4;$ what will be the new value of arithmetic mean.

Answer 1

$\left(a\right)$ Mean $=\sum x/n$
Here, $n=9$
Thus,
Mean $=(60+67+52+76+50+51+74+45+56)/9=531/9=59$
$\left(b\right)$ If the marks of each student be increased by 4 then new arithmetic mean will be $=59+4=63$