If , then =

We have given,



Also,



Putting this in above equation






Now, given …[1]


using this


We have,




…[2]


We know,


If x1, x2, … , xn are observations with frequencies f1, f2, … , fn i.e. x1 occurs f1 times and x2 occurs f2 times and so on, then mean() of observations is given by



From [1] and [2]


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