Question

The mean $\overline{x}$ of a grouped data is given by:

• A. $\frac{\sum f_i{x}_i}{\sum f_i}$
• B. $\frac{\sum f_i}{x_i}$
• C. $\frac{\sum x_i}{f_i}$
• D. $\frac{\sum f_i{x}_i}{\sum x.f}$

Answer 1

The correct option is A

$\frac{\sum f_i{x}_i}{\sum f_i}$

For grouped data, using the direct method first, we find the sum of the values of all the observations after multiplying them with their respective frequencies. Then we divide this result by the total number of observations (sum of all frequencies).