Find out the median of the following frequency distribution:

Variable	11	12	13	14	15	16	17	18	Total
Frequency	5	7	11	9	8	7	3	5	55

The median is the middle value when data is arranged in order.

Total frequency $n = 55$

Median position $= \dfrac{n + 1}{2}$

$= \dfrac{55 + 1}{2}$

$= \dfrac{56}{2}$

$= 28$

The median is the 28th value in the data.

---

Constructing the cumulative frequency table:

Variable	Frequency	Cumulative Frequency
11	5	5
12	7	12
13	11	23
14	9	32
15	8	40
16	7	47
17	3	50
18	5	55

---

The 28th value needs to be located:

After variable 13: cumulative frequency = 23 (less than 28)

After variable 14: cumulative frequency = 32 (greater than 28)

The 28th value falls in the class with variable 14.

Therefore, the median is $14$.