Question

The frequency table of the ages of 40 students in a class is given below. Find their mean age.

Age of students (in years)	11	12	13	14
Frequency	16	10	12	2

Answer 1

$$\begin{gathered} \overline{\mathrm{X}}=\frac{\mathrm{Total}\left(x\times f\right)}{\mathrm{N}} \\ =\frac{480}{40} \\ =12 \end{gathered}$$

Therefore, the mean age is 12 years.