Question

( 4.)Out of 10 students, who appeared in a test,
three secured less than 30 marks and 3
secured more than 75 marks. The marks
secured by the remaining 4 students are 35,
48, 66 and 40. Find the median score of the
whole group.​

Answer 1

There is a mistake in this question. The total students are 10 but the marks are given only of 9 students. So, I am solving this question assuming that the students are 9.

Let the marks of those students who scored less than 35 marks be a, b, c and marks of the students who scored more than 70 marks be x, y, z.

The ascending order of the marks = a, b, c, 39, 43, 51, x, y, z

Now,

Median = (n + 1)/2

= (9 + 1)/2

10/2 = 5

so, 5th observation is 43.

So, the median score of the whole group is 43 marks.

Answer 2

Answer:

(1)   Marks obtained by 3 students less than 30 be : a, b, c.

(2)  Marks obtained by 3 students more than 75 be : x, y, z.

(3)  Marks obtained by the remaining 4 students are  : 35, 48  66, 40.

Ascending Order = a, b, c, 35, 40, 48, 66, x, y , z.

Number of observations = 10.

Median = [ (n/2) th +  ( n/2 + 1 )] terms /2                    

 

Median =  (5th + 6th) terms /2

             =40+48/2

            =  88/2

             =44 .              (ans).