Q.

Marks obtains by all the students of class 12 are presented in a frequency distribution with classes of equal width. Let the median of this grouped data be 14 with median class interval 12-18 and median class frequency 12. If the number of students whose marks are less than 12 is 18, then the total number of students is          [2025]

1 48  
2 52  
3 40  
4 44  

Ans.

(4)

In the given question, l = 12, cf = 18, median = 14, f = 12 and h = 6

∴  Median = l+(N2–cff)×h

⇒ 14=12+(N2–1812)×6

⇒ 2=N2–182 ⇒ 4=N2–18

⇒ N2=22 ⇒ N=44

So, total number of students = 44.