Question

In the calculation of standard deviation for grouped data (mean method), $d_i$ = ____?

• A. $d_i=x_i-\overline{x}$
• B. $d_i=a_i-\overline{x}$
• C. $d_i=\overline{x}-x_i$
• D. $d_i=\overline{x}-a_i$
  

Answer 1

The correct option is A $d_i=x_i-\overline{x}$

$\sigma =\sqrt{\frac{\sum f_i{d}_i^2}{N}}$ (mean method)

where, $d_i=x_i-\overline{x}$ and $N=\sum f_i$