In a set of 20 observations, each of the observation below the median of all observations is increased by 6 and each of the remaining observation is decreased by2.Then the mean of the new set of observations

Arrange all observations in increasing or decreasingorder.Let the observations be x1,x2…x20 so that  x10+x112 .is themedian. The new set of observations will be  x1+6,…x10+6,x11−2,…,x20−2Their mean is equal to                                120∑i=120 xi+6×10−2×10=120∑i=120 xi+2