Question

The mean of $10$ observation is $20$. if each observation is added by ${}^{\prime }{5}^{\prime }$. Find the mean of new observation.

Answer 1

Given Mean of $10$ observations is $20$

$⟹$Sum of $10$ observations is $S=20\times 10=200$

If each observation is added by $5$ Then sum of observations is added by $5\times 10=50$

$⟹S^{\prime }=200+50=250$

Mean of new observation is $\frac{S^{\prime }}{10}=\frac{250}{10}=25$