In the formula, bar x = { A + Σfidi/Σfi} for the following the mean of the grouped data, the di’s are the deviations from A of ​

Question

In the formula, \(\bar{x}\) = \(\{A +\frac{\sum f_id_i}{\sum f_i}\}\) for the following the mean of the grouped data, the d_i’s are the deviations from A of 

(a) lower limits of the classes 

(b) upper limits of the classes 

(c) midpoints of the classes 

(d) none of these

Answer 1

The d_i′ s are the deviations from A of midpoints of the classes.