If the mean of the set of numbers x1,x2,....xn is ¯x, then the mean of the numbers xi+2i,1≤i≤n is
For the given distinct values x1,x2,x3,.....xn occurring with frequencies f1,f2,f3,...fn respectively. The mean deviation about mean where ¯¯¯x is the mean and N is total number of observations would be