Following distribution gives the marks scored by a class of 20 students. If 10 students scored below
14.4 and remaining 10 scored above 14.4, find values of x and y.
Marks
I 06 I 6-12 I 12-18 I 18-24 I 2430
No. of Students 4
x
5
y
1
..
Answers
x = 4 and y = 6
Step-by-step explanation:
Marks 0-6 ; 6-12 ; 12-18 ; 18-24 ; 24-30
Student 4 ; x ; 5 ; y ; 1
Total number of student = 20
So we get x + y = 10 -----(1)
Median = 14.4
Median class is 12-18.
Median = L + (n/2-C) / f * w
14.4 = 12 + [20/2 - (4+x)]/ 5 * 6
14.4 * 5 = 60 + (10 - 4 - x) * 6
72 = 60 + 60 - 24 - 6x
6x = 120 - 24 - 72
6x = 24
x = 24/ 6
x = 4
Substituting in (1), we get 4+ y = 10
Therefore y = 6.
Answer:
Step-by-step explanation:
Marks 0-6 ; 6-12 ; 12-18 ; 18-24 ; 24-30
Student 4 ; x ; 5 ; y ; 1
Total number of student = 20
So we get x + y = 10 -----(1)
Median = 14.4
Median class is 12-18.
Median = L + (n/2-C) / f * w
14.4 = 12 + [20/2 - (4+x)]/ 5 * 6
14.4 * 5 = 60 + (10 - 4 - x) * 6
72 = 60 + 60 - 24 - 6x
6x = 120 - 24 - 72
6x = 24
x = 24/ 6
x = 4
Substituting in (1), we get 4+ y = 10
Therefore y = 6.