Page 3 - Lesson Note MCT 2 52

Answer: -

Size(X) Frequency (F) Cumulative frequency (CF)
3 2 2
4 1 3
5 3 6

6 7 13
7 4 17
= ∑ = 17

+1
Me = size of [ ]th item
2
17+1
= size [ ]th item.
2
= 9th item falls in the cumulative frequency 13, therefore,Me = 6.

Steps to calculate Median in case of Continuous series: -

Step 1: Arrange the data in ascending or descending order and convert the
data set into continuous series exclusive form.

Step 2: Calculate the c.f.

Step 3: Find the median item as: Me = size of [ ]th item.
2

Step 4: Find out c.f. which is either equal to or just greater them this.

Step 5: Find the class corresponding to c.f. equal to or just greater than this.
This class is called median class.

− .
Step 6: Me = + 2 ×
1

Where, =refers to lower limit of median class.
1

= refers to median th data.
2
c.f = refers to cumulative of the class preceding the median class.

F = refers to frequency of the median class.

i = refers to difference of median class.

Ex: find the median of the following data:

X 0 - 10 10 - 20 20 - 30 30 - 40 40 - 50

F 3 4 2 7 9