question_answer

For a frequency distribution, standard deviation is computed by

A)                 \[\sigma =\frac{\sum f(x-\bar{x})}{\sum f}\]      

B)                 \[\sigma =\frac{\sqrt{\sum f{{(x-\bar{x})}^{2}}}}{\sum f}\]

C)                 \[\sigma =\sqrt{\frac{\sum f{{(x-\bar{x})}^{2}}}{\sum f}}\]

D)                 \[\sigma =\sqrt{\frac{\sum f(x-\bar{x})}{\sum f}}\]