Question

WHY NO ONE SOLVES VERY DIFFICULT QUES HERE??WHY YOU ALL PREDER EASY QUES PLS SOLVE MY QUESSSS The mean of the values 1, 2, 3, …….n with respective frequencies x, 2x, 3x …… nx is?????

Answer 1

Answer:

Given F: 1 2 3..........n

X:x 2x 3x......NC

Mean=f1x1+f2x2.....fnxn/f1+f2+f3...fn

=1×x+2×2x+3×3x....n×nx/x+2x..NC

=1+4+9....n^2/1+2+3...n

=n(n+1)(2n+1)/6/n(n+1)/2

=2n+1/3