Consider the following table :

Diameter of heart (in mm)	Number of persons
120	5
121	9
122	14
123	8
124	5
125	9

The median of the above frequency distribution is :

1. 122 mm

2. 122.5 mm

3. 122.75 mm

4. 123 mm

Cumulative frequency distribution table is as follows :

Here n = 50, which is even.

By formula,

Median = $\dfrac{\dfrac{\text{n}}{2} \text{ th observation} + \Big(\dfrac{\text{n}}{2} + 1\Big) \text{ th observation}}{2}$

$= \dfrac{\dfrac{50}{2} \text{ th observation} + \Big(\dfrac{50}{2} + 1\Big) \text{ th observation}}{2} \\[1em] = \dfrac{25 \text{ th observation} + \Big(25 + 1\Big) \text{ th observation}}{2} \\[1em] = \dfrac{25 \text{ th observation} + 26 \text{ th observation}}{2} \\[1em] = \dfrac{122 + 122}{2} \\[1em] = \dfrac{244}{2} \\[1em] = 122 \text{ mm}.$

Since, all observations from 25th to 26th corresponds to 122 mm.

Hence, Option 1 is the correct option.