Worksheet on Statistics for Class 12

Solved Questions on Statistics

1. What is the mode of the given data set?

4, 4, 4, 9, 15, 15, 15, 4, 27, 37 and 48

a) 4
b) 9
c) 15
d) 27

Answer: a) 4

Explanation: Mode is the data point that appears the most number of times in the given dataset.
So, the given set is 4, 4, 4, 9, 15, 15, 15, 4, 27, 37 and 48
Hence, here the number 4 is the mode of the data.

2. Find the mean of the following dataset: 8, 12, 5, 20, 15.

a) 8
b) 12
c) 16
d) 20

Answer: b) 12

Explanation: Mean = (Sum of all values) / (Number of data points/observations)
= (8 + 12 + 5 + 20 + 15) / 5
= 60/5
= 12

3. The ages of five students in a class are 12, 14, 15, 13 and 16. What is the average age of the students?

a) 8
b) 12
c) 14
d) 20

Answer: c) 14

Explanation:
Mean = (Sum of all values) / (Number of data points/observations)
= (12 + 14 + 15 + 13 + 16) / 5
= 70/5
= 14

The average age of the students is 14.

4. Calculate the median of the following dataset: 24, 26, 21, 28, 22, 29, 23.

a) 10
b) 12
c) 20
d) 24

Answer: d) 24

Explanation: Arrange the data in ascending order:
21, 22, 23, 24, 26, 28, 29
n = 7
Median formula for an odd number of observations
= (n + 1)/2
= (7 + 1)/2
= 8/2
= 4^th

In the given data 24 is in the 4^th position. So, the median of the given data is 24

5. Find the median of the following dataset: 10, 9, 8, 12, 11, 7, 6, 13.

a) 10
b) 12
c) 14
d) 16

Answer: a) 10

Explanation: Arrange the data in ascending order:
6, 7, 8, 9, 10, 11, 12, 13
n = 8
Median formula for an even number of observations
= [(n/2)^th + (n/2 + 1)^th] / 2
= [(8/2)^th + (8/2 + 1)^th / 2
= (4th + 5th) / 2
= (9 + 10) / 2
= 19 / 2
= 9.5

So, the median of the given data is 9.5.

Practice Questions on Statistics

1. What is the mode of the given data set?

12, 15, 12, 16, 8, 16, 8, 5, 7 and 12

a) 8
b) 12
c) 15
d) 16

Answer: b) 12

2. Calculate the median of the following dataset: 8, 12, 16, 5, 10.

a) 10
b) 12
c) 20
d) 24

Answer: a) 10

3. The average weight of six people is 68 kg. If the weights of five of them are 70, 75, 72, 65 and 68 kg, what is the weight of the sixth person?

a) 42
b) 48
c) 58
d) 65

Answer: c) 58

4. The ages of seven individuals are 22, 24, 25, 22, 21, 26 and 24. What is the mode of their ages?

a) 22
b) 24
c) Both (a) and (b)
d) 26

Answer: c) Both (a) and (b)

5. The ratio of the mode and the median of a set of values is 5 : 8. Find the ratio of their mean and mode.

a) 2 : 3
b) 4 : 7
c) 8 : 5
d) 7 : 11

Answer: c) 8 : 5

6. Find the mode for the following data.

a) 0
b) 1
c) 2
d) 3

Answer: c) 2

7. Find the mean of the following dataset: 18, 12, 5, 20, 15.

a) 12
b) 14
c) 16
d) 20

Answer: b) 14

8. Find the mean of the following dataset: 35, 70, 58, 20, 68, 55.

a) 32
b) 39
c) 45
d) 51

Answer: d) 51

9. Calculate the median of the following dataset: 54, 60, 48, 36, 23, 45, 88.

a) 60
b) 23
c) 36
d) 48

Answer: d) 48

10. What is the mode of the given data set?

2, 5, 2, 5, 5, 7, 6, 5, 7, 10, 12, 2, 2

a) 2
b) 5
c) Both (a) and (b)
d) 7

Answer: c) Both (a) and (b)