JEE Main 2014 (Online) 9th AprilQuestion 1
In a set of $2n$ distinct observations, each of the observation below the median of all the observations is increased by $5$ and each of the remaining observations is decreased by $3$. Then, the mean of the new set of observations :
Statistics
Solution
$n$ observations rise by $5$ and $n$ fall by $3$: net change $2n$ over $2n$ observations, so mean increases by $1$.