For calculating the median, we prepare the cumulative frequency distribution table as given below :
n = 60
⇒ 45 + x + y = 60
⇒ x + y = 60 – 45
⇒ x + y = 15 …(1)
Median is 28-5, which lies in the class 20 – 30.
So, it is the median class.
∴ l = 20, f = 20, cf = 5 + x and h = 10.
Putting the value of x in equation (1), we get y = 7
⇒ y= 15 – 8 = 7
Hence, x = 8, y = 7
