Pearson's Coefficient of skewness is defined as:: (A) (Mean-Mode) / SD, (B) (Median-Mode) / SD, (C) SD / (Mean - Mode), (D) SD / (Median -Mode)
Answer is A. The coefficient used for checking the skewness of data, is called as the Karl Pearson coefficient, and is calculated as (Mean - Mode) S.D. Ref: Instant Medical Biostatistics, By Ranjan Das, Papri N. Das, 2009 Ane's Instant Medical Series, Page 41, 42.