Question

the mean deviation of the data 1,2,3,4

Answer 1

Let us take 2 as assumed mean.

Now,let us write mean deviations

x1=1-2=-1

x2=2-2=0

x3=3-2=1

x4=4-2=2

Sum of mean deviations=-1+0+1+2

                                      =2

X=2/4

  =1/2

Mean=2+1/2

        =5/2

       =2.5