Question

The mean of a certain number of observations is $35$. What is the new value of the mean if each observation is divided by $5$.

• A. $6$
• B. $7$
• C. $8$
• D. $9$

Answer 1

The correct option is B $7$

Let the count of observations is $N$

Mean $=\frac{\text{Sum of observations}}{N}=35$ ....given

Sum of observations $=35N$

If each observation is divided by $5$, then $\frac{1}{5}$ can be taken out as common from each observation.

Therefore new sum of observations $=\frac{1}{5}\times 35N=7N$..

So, the new mean $=\frac{7N}{N}=7$