JEE Main 20208 Jan, Morning shiftMathematicsMediumStatistics and Probability258× since 2002
The mean and the standard deviation (s.d.) of
10 observations are 20 and 2 resepectively.
Each of these 10 observations is multiplied by
p and then reduced by q, where p 0 and
q 0. If the new mean and new s.d. become
half of their original values, then q is equal to