CBSE - Statistics

1 Statistics 

A school has 20 teachers, one of them retires at the age of 60  years and a new teacher replaces him, this  change reduces the average  age of the staff by 2 years,  the age of new teacher is 

(1) 28 years
(2) 25 years
(3) 20 years
(4) 18 years

2 Statistics 

The median of first 12 prime numbers is : 

(1) 13  
(2) 14 
(3) 15 
(4) 17

3 Statistics 

When 10  is subtracted from all the observations, the mean is reduced to 60%  of its value. If 5 is added to all the observations, then the mean will be

(1) 25
(2) 30 
(3) 60
(4) 65 

4 Statistics 

The highest score of a certain data exceeds in lowest score by 16 and coefficient of range is 1/3. The sum of the highest score and the lowest score is

(1) 36
(2) 48
(3) 24
(4) 18

5 Statistics 

The mean age of a combined group of men and women is 25 years. If the mean age of the group of men is 26 and that of the group of women is 21, then the percentage of men and women in the group is

(1) 60, 40
(2) 80, 20
(3) 20, 80
(4) 40, 60

6 Statistics 

The highest score of a certain data exceeds in lowest score by 16 and coefficient of range is 1/3. The sum of the highest score and the lowest score is

(1) 36
(2) 48 
(3) 24
(4) 18

7 Statistics 

Following table gives the number of trees planted by the students in a school on ' Environment Day, Observe the table and find mode of the trees planted by the students.

1) 80
2) 50
3) 45
4) 35

8 Statistics 

If y=f(x) be a monotonically increasing or decreasing function of x and M is the median of variable x, then the median of y is

(1) f(M)
(2) M/2
(3) f⁻¹(M)
(4) none of these

9 Statistics 

If the median of the data x1,x2,x3,x4,x5,x6,x7,x8 is α and x1<x2<x3<x4<x5<x6<x7<x8, then the median of x3,x4,x5,x6 is

(1) α
(2) α / 2
(3) α / 3
(4) α / 4

10 Statistics 

If number 6, 8, 2x – 5, 2x – 1, 15, 17, 20 and 22 are in asending order and its mediun is 14 t hen the value of x will be

(1) 14 
(2) 7 
(3) 15 
(4) 20