CBSE - Statistics

1 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

2 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 

3 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

4 Statistics 

If the mean of the lower and upper quartile is 10 and semi-interquartile range is 5, then the lower quartile and upper quartile respectively are

(1) 2 and 12
(2) 3 and 13
(3) 4 and 14
(4) 5 and 15

5 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

6 Statistics 

The mean and median of the data x,y,z are 50 and 35respectively, where x<y<z. If z−x=55, then the value of (y−x) is

(1) 8
(2) 7
(3) 3
(4) 5

7 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

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 

The median of first 12 prime numbers is : 

(1) 13  
(2) 14 
(3) 15 
(4) 17

10 Statistics 

The median from the following distribution is 

(1) 19
(2) 19.5
(3) 20
(4) 18