during the medical check up of …

More than method: cumulative frequency

On X-axis plot lower class limits.On Y-axis plot cumulative frequency. 
We plot the points (38,35),(40,32),(42,30),(44,26),(46,26),(48,7),(50,3).
Less than method :

On x-axis plot upper class limits.On Y-axis plot cumulative frequency
We plot the points (38,0),(40,3),(42,5),(44,9),(46,4),(48,28),(50,32),(52,35).

We find the two types of curves intersect at a point P. From point P perpendicular PM is draw on x-axis
The verification,
We have
Now, N = 35
{tex}\frac { N } { 2 } = 17.5{/tex}
The cumulative frequency just greater than {tex}\frac {N}{2}{/tex} is 28 and the corresponding class is 46 - 48.
Thus 46 - 48 is the median class such that
L = 46, f = 14, C₁ = 14 h = 2
Median {tex}= L + \frac { \frac { N } { 2 } - c _ { 1 } } { f } \times h{/tex}
{tex}= 46 + \frac { 17.5 - 14 } { 14 } \times 2{/tex}
{tex}= 46 + \frac {7}{14}{/tex}
= 46.5
Median = 46.5 kg
Hence verified.