If the median of the distribution given below is 28.5, find the values of x and y.

Class interval	Frequency
0-10	5
10-20	x
20-30	20
30-40	15
40-50	y
50-60	5
Total	60

Given: Median = 28.5 and n = Σfi = 60
We have, n = 60 ⇒ n/2 = 30
Since the median is given to be 28.5, thus the median class is 20-30.
Therefore n/2 = 30, l = 20, f = 20, cf = 5 + x, and h = 10
Substituting these values in the formula
Median = l + ((n/2 - cf)/f) × h
⇒ 28.5 = 20 + ((30 - (5 + x))/20) × 10
⇒ 28.5 = 20 + (25 - x)/2
⇒ 57 = 40 + 25 - x
⇒ x = 8
Also, 45 + x + y = 60
with x = 8, we get y = 7
Hence, (x, y) = (8, 7)