Question

The following table shows the number of patients of different age groups admitted to a hospital for treatment on a day. Find the median of ages of the patients.

Age- group (Yrs.)	10-20	20-30	30-40	40-50	50-60	60-70
No. of patients	40	32	35	45	33	15

 

Answer 1

Age (Yrs.)	No. of patients (Frequency)	Cumulative frequency (Less than)
10-20	40	40
20-30	32	72
30-40	35	107
40-50	45	152
50-60	33	185
60-70	15	200

Here N = 200     ∴ the number` N/2=`100 which is included in the class 30-40

∴ median class is 30 - 40
∴ L = 30, cf = 72, f = 35, h = 10

Median = L+ `|(n/2-cf)/f| xx h`

             `=30+((100-72)/35) xx 10`

              `=30+(28xx2)/7`

             = 30 + 4 x 2

             = 30 + 8 = 38 

∴ median of ages of patients is 38.