Question 22
Find the mode of the following distribution of marks obtained by the students in an examination:
Marks obtained
0 – 20
20 – 40
40 – 60
60 − 80
80 − 100
Number of Students
15
18
21
29
17
Given the mean of the above distribution is 53, using empirical relationship estimate the value of its median.
Mode = l + (𝑓1 −𝑓0)/(2𝑓1 −𝑓0 −𝑓2) × h
Modal class = Interval with highest frequency
= 60 – 80
where l = lower limit of modal class h = class-interval
f1 = frequency of the modal class
f0 = frequency of the class before modal class
f2 = frequency of the class after modal class
Lifetimes (in hours)
Frequency
0 – 20
15
20 – 40
18
40 – 60
21
60 – 80
29
80 – 100
17

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.