CBSE - Statistics

1 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

2 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

3 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

4 Statistics 

From the following table, what was the value of the cumulative price for the product tablet?
 

(1) 300
(2) 310 
(3) 320
(4) 330

5 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

6 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

7 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

8 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

9 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%

10 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