If μ is the mean of distribution yi, fi then ∑ fi (yi - μ) is equal to

Question

If μ is the mean of distribution yi, fi then ∑ fi (yi - μ) is equal to (A) M.D. (B) S.D. (C) 0 (D) relative frequency

Tardigrade Admin · Accepted Answer

∑ fi(yi - μ) = ∑(fi yi - fiμ) = ∑ fi yi - μ∑ fi =∑ fiyi - ((∑ fiyi/∑ fi)) ∑ fi = 0

Q. If $μ$ is the mean of distribution ${y_{i}, f_{i}}$ , then $\sum f_{i} (y_{i} - μ)$ is equal to