The various steps in the computations of median in a discrete series are as follows:
(i) Arrange the values in ascending or descending order of magnitude.
(ii) Find out the cumulative frequencies.
(iii) Find out the middle item by the formula N + 1/ 2
(iv) Now find out the value of (N + 1/2) th item. It can be found by first locating the cumulative frequency which is equal to or (N + 1/2) next higher to it, and then determining the value corresponding to it. This will be the value of the median.
Finding the Value of Median
Solved Example: Find out the value of median from the following data.
|
Daily wages ($) |
10, |
5, |
7, |
11, |
8 |
|
Number of Workers |
15 |
20 |
15 |
18 |
12 |
Solution: Calculation of median
|
Wages in ascending order ($) |
Number of |
Cumulative |
|
5 |
20 |
20 |
|
7 |
15 |
35 |
|
8 |
12 |
47 |
|
10 |
15 |
62 |
|
11 |
18 |
80 |
Median is the value of (N+1)/2)th or ((80+1)/2)th or 40.5th item.
All items from 35 onwards up to 47 have a value of 8. Thus the median value would be $ 8.