​I did not get this question...please this time do answer it and dont ask the exact location....it is the 3rd question of first topic test of chapter statiscs of class 11th

Dear Student,
Please find below the solution to the asked query:

a,a+d,a+2d,....a+nd is Arithmetic Progression of of n terms.We know that:Sum of n terms of an A.P.=n2First term+Last term=n2a+a+nd=n22a+ndMean=X¯=Sum of n terms n=n22a+ndn=2a+nd2Now sum of deviations about the mean is :S=a-2a+nd2+a+d-2a+nd2+.....+a+n-1d-2a+nd2+a+nd-2a+nd2=2a-2a-nd2+2a+2d-2a-nd2+.....+2a+2nd-2d-2a-nd2+2a+2nd-2a-nd2=-nd2+2d-nd2+.....+nd-2d2+2nd-nd2=-nd2-nd-2a2+.....+nd-2d2+nd2As you can see first and last term will cancel out each other, second and second last term will cancel out each other.Similarly all terms will cancel out each oS=0OptionA is correct.

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