Question

If each item is reduced by 15, arithmetic mean is :
(A) Reduced by 15
(B) Increased by 15
(C) Reduced by 10
(D) None of these​

Answer 1

Answer:

reduced by 15

Step-by-step explanation:

maybe it's the answer

Answer 2

Given:

Each term in a sequence is reduced by 15.

To FInd:

Change in arithmetic mean.

Solution:

The arithmetic mean of a sequence having $n$ terms $a_1,a_2,...,a_n$ is given by

          $AM=\frac{a_1+a_2+...+a_n}{n}$

If each term is reduced by 15, new terms will be as follows                                                        

        $(a_1-15),(a_2-15),...,(a_n-15)$

New arithmetic mean,

        $AM'=\frac{(a_1-15)+(a_2-15)+...+(a_n-15)}{n}$

   ⇒ $AM'=\frac{(a_1+a_2+...+a_n)-15n}{n}$

   ⇒ $AM'=AM-15$

Hence, if each term of a sequence is reduced by 15, then the arithmetic mean will also get reduced by 15.