The marks obtained by 80 students in a test are given below:


Marks



4



12



20



28



36



44



Number of students



8



10



16



24



15



7



Find the modal marks.

We can draw the table as below,


Marks (x)



Number of students (f)



Cumulative frequency



Fx



4



8



8



32



12



10



18



120



20



16



36



320



28



24



60



672



36



15



75



540



44



7



80



308




N = 80




∑fx = 1992



We have;


N = 80 (even number)


Median =





Now,


∑fx = 1992 and ∑f = N = 80


Mean =


Hence,


Mode = 3(median) – 2 (mean)


= 3×28 - 2×24.9


= 84 –49.8


= 34.2


10