If a variable X has taken n values and its mean is X' then the standard deviation is given by
[tex]s\text{d}=\sqrt[]{\frac{(X_1-X^{\prime})^2+(X_2-X^{\prime})^2+\cdots+(X_n-X^{\prime})^2}{n-1}}[/tex]
Given data:
It is given that that there are 12 eggs and there weights are
[tex]\begin{gathered} 67,67,68,69,69,70 \\ 71,71,71,72,72,73 \end{gathered}[/tex]
and there mean weight is 70 grams.
So n=12 and X'=70
So, standard deviation will be
[tex]\begin{gathered} sd=\sqrt[]{\frac{(67-70)^2+(67-70)^2+\cdots+(73-70)^2}{12-1}} \\ sd=\sqrt[]{\frac{(67-70)^2+(67-70)^2+\cdots+(73-70)^2}{11}} \end{gathered}[/tex]
So, the correct option is A.
