Consider the marks obtained (out of $100$ marks) by $30$ students of Class $IX$ of a school:
$\begin{array}{*{20}{c}}
{10}&{20}&{36}&{92}&{95}&{40}&{50}&{56}&{60}&{70} \\
{92}&{88}&{80}&{70}&{72}&{70}&{36}&{40}&{36}&{40} \\
{92}&{40}&{50}&{50}&{56}&{60}&{70}&{60}&{60}&{88}
\end{array}$

(N/A) Recall that the number of students who have obtained a certain number of marks is called the frequency of those marks. For instance,$4$ students got $70$ marks. So the frequency of $70$ marks is $4$. To make the data more easily understandable,we write it in a table,as given below:

Marks	Number of students (i.e.,the frequency)
$10$	$1$
$20$	$1$
$36$	$3$
$40$	$4$
$50$	$3$
$56$	$2$
$60$	$4$
$70$	$4$
$72$	$1$
$80$	$1$
$88$	$2$
$92$	$3$
$95$	$1$
Total	$30$

This table is called an ungrouped frequency distribution table,or simply a frequency distribution table. Note that you can also use tally marks in preparing these tables.