CBSE - Statistics

1 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 

2 Statistics 

The mean yearly salary of an employee of acompany was Rs. 20,000. If the mean yearly salaries of male and female employees were Rs. 20800 and Rs. 16800  respectively, then the percentages of males and females employed in the company respectively are

(1) 80% and 20%
(2) 70% and 30%
(3) 55% and 45%
(4) 50% and 50%

3 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

4 Statistics 

The median of first 12 prime numbers is : 

(1) 13  
(2) 14 
(3) 15 
(4) 17

5 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

6 Statistics 

Compute mode for the following data

7, 7, 8, 8, 8, 9, 9, 10, 10, 10, 11, 11, 12, 13, 13

1) 10.4
2) 10.2
3) 9.8
4) 10.5

7 Statistics 

The median from the following distribution is 

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

8 Statistics 

The arithmetic mean and mode of a data are 24 and 12 respectively, Then the median of the data is 

(1) 20
(2) 18
(3) 21
(4) 22

9 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

10 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