Find the median from the following data.

Age in years	15 - 25	25 - 35	35 - 45	45 - 55	55 - 65	65 - 75	75 - 85
No. of patients	11	18	22	30	40	16	33

Correct option is C

Given:

Formula Used:

Median for grouped data :

Median = L + $$\left( \frac{\frac{N}{2} - F}{f} \right) \times h$$​​

Where:

L = lower boundary of the median class

N = total frequency

F = cumulative frequency before the median class

f = frequency of the median class

h = class width

Solution:

Total Frequency (N) = 11 + 18 + 22 + 30 + 40 + 16 + 33 = 170

Median Position = $$\frac{N}{2} = \frac{170}{2}$$​ = 85

Median Class: 55 – 65

Now, L = 55, F = 81, f = 40, h = 10

Median = 55 + $$\left( \frac{85 - 81}{40} \right) \times 10$$​​

= 55 + $$\left( \frac{4}{40} \right) \times 10$$​​

= 55 + 1 = 56 years